VOL-2076 Unit Test cases for core.go

Change-Id: Ie003cd248478679404107d985c1a22a381e6348c
diff --git a/vendor/modules.txt b/vendor/modules.txt
index f8f8444..07cb89d 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -23,17 +23,17 @@
 # github.com/eapache/queue v1.1.0
 github.com/eapache/queue
 # github.com/gogo/protobuf v1.3.0
-github.com/gogo/protobuf/proto
 github.com/gogo/protobuf/gogoproto
+github.com/gogo/protobuf/proto
 github.com/gogo/protobuf/protoc-gen-gogo/descriptor
 # github.com/golang/protobuf v1.3.2
-github.com/golang/protobuf/ptypes/empty
-github.com/golang/protobuf/ptypes
-github.com/golang/protobuf/ptypes/any
+github.com/golang/protobuf/descriptor
 github.com/golang/protobuf/proto
 github.com/golang/protobuf/protoc-gen-go/descriptor
-github.com/golang/protobuf/descriptor
+github.com/golang/protobuf/ptypes
+github.com/golang/protobuf/ptypes/any
 github.com/golang/protobuf/ptypes/duration
+github.com/golang/protobuf/ptypes/empty
 github.com/golang/protobuf/ptypes/timestamp
 # github.com/golang/snappy v0.0.1
 github.com/golang/snappy
@@ -63,23 +63,25 @@
 # github.com/mitchellh/mapstructure v1.1.2
 github.com/mitchellh/mapstructure
 # github.com/opencord/voltha-lib-go/v2 v2.2.7
-github.com/opencord/voltha-lib-go/v2/pkg/log
-github.com/opencord/voltha-lib-go/v2/pkg/db/kvstore
-github.com/opencord/voltha-lib-go/v2/pkg/grpc
-github.com/opencord/voltha-lib-go/v2/pkg/probe
-github.com/opencord/voltha-lib-go/v2/pkg/version
-github.com/opencord/voltha-lib-go/v2/pkg/db/model
-github.com/opencord/voltha-lib-go/v2/pkg/kafka
-github.com/opencord/voltha-lib-go/v2/pkg/flows
-github.com/opencord/voltha-lib-go/v2/pkg/adapters/common
 github.com/opencord/voltha-lib-go/v2/pkg/adapters
 github.com/opencord/voltha-lib-go/v2/pkg/adapters/adapterif
+github.com/opencord/voltha-lib-go/v2/pkg/adapters/common
+github.com/opencord/voltha-lib-go/v2/pkg/db/kvstore
+github.com/opencord/voltha-lib-go/v2/pkg/db/model
+github.com/opencord/voltha-lib-go/v2/pkg/flows
+github.com/opencord/voltha-lib-go/v2/pkg/grpc
+github.com/opencord/voltha-lib-go/v2/pkg/kafka
+github.com/opencord/voltha-lib-go/v2/pkg/log
+github.com/opencord/voltha-lib-go/v2/pkg/probe
+github.com/opencord/voltha-lib-go/v2/pkg/version
 # github.com/opencord/voltha-protos v1.0.3
 github.com/opencord/voltha-protos/go/common
-github.com/opencord/voltha-protos/go/voltha
-github.com/opencord/voltha-protos/go/openflow_13
 github.com/opencord/voltha-protos/go/inter_container
 github.com/opencord/voltha-protos/go/omci
+github.com/opencord/voltha-protos/go/openflow_13
+github.com/opencord/voltha-protos/go/voltha
+# github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
+github.com/phayes/freeport
 # github.com/pierrec/lz4 v2.3.0+incompatible
 github.com/pierrec/lz4
 github.com/pierrec/lz4/internal/xxh32
@@ -90,20 +92,20 @@
 # github.com/stretchr/testify v1.4.0
 github.com/stretchr/testify/assert
 # go.etcd.io/etcd v0.0.0-20190930204107-236ac2a90522
-go.etcd.io/etcd/clientv3
-go.etcd.io/etcd/clientv3/concurrency
-go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes
 go.etcd.io/etcd/auth/authpb
+go.etcd.io/etcd/clientv3
 go.etcd.io/etcd/clientv3/balancer
+go.etcd.io/etcd/clientv3/balancer/connectivity
 go.etcd.io/etcd/clientv3/balancer/picker
 go.etcd.io/etcd/clientv3/balancer/resolver/endpoint
+go.etcd.io/etcd/clientv3/concurrency
 go.etcd.io/etcd/clientv3/credentials
+go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes
 go.etcd.io/etcd/etcdserver/etcdserverpb
 go.etcd.io/etcd/mvcc/mvccpb
 go.etcd.io/etcd/pkg/logutil
-go.etcd.io/etcd/pkg/types
-go.etcd.io/etcd/clientv3/balancer/connectivity
 go.etcd.io/etcd/pkg/systemd
+go.etcd.io/etcd/pkg/types
 go.etcd.io/etcd/raft
 go.etcd.io/etcd/raft/confchange
 go.etcd.io/etcd/raft/quorum
@@ -115,43 +117,44 @@
 go.uber.org/multierr
 # go.uber.org/zap v1.10.0
 go.uber.org/zap
-go.uber.org/zap/zapcore
-go.uber.org/zap/internal/bufferpool
 go.uber.org/zap/buffer
+go.uber.org/zap/internal/bufferpool
 go.uber.org/zap/internal/color
 go.uber.org/zap/internal/exit
+go.uber.org/zap/zapcore
 # golang.org/x/crypto v0.0.0-20191001170739-f9e2070545dc
 golang.org/x/crypto/md4
 golang.org/x/crypto/pbkdf2
 # golang.org/x/net v0.0.0-20190930134127-c5a3c61f89f3
-golang.org/x/net/trace
-golang.org/x/net/internal/timeseries
+golang.org/x/net/context
+golang.org/x/net/http/httpguts
 golang.org/x/net/http2
 golang.org/x/net/http2/hpack
-golang.org/x/net/proxy
-golang.org/x/net/http/httpguts
 golang.org/x/net/idna
-golang.org/x/net/context
 golang.org/x/net/internal/socks
+golang.org/x/net/internal/timeseries
+golang.org/x/net/proxy
+golang.org/x/net/trace
 # golang.org/x/sys v0.0.0-20191001151750-bb3f8db39f24
 golang.org/x/sys/unix
 # golang.org/x/text v0.3.2
 golang.org/x/text/secure/bidirule
+golang.org/x/text/transform
 golang.org/x/text/unicode/bidi
 golang.org/x/text/unicode/norm
-golang.org/x/text/transform
 # google.golang.org/genproto v0.0.0-20190927181202-20e1ac93f88c
 google.golang.org/genproto/googleapis/api/annotations
 google.golang.org/genproto/googleapis/rpc/status
 # google.golang.org/grpc v1.24.0
 google.golang.org/grpc
-google.golang.org/grpc/codes
-google.golang.org/grpc/metadata
-google.golang.org/grpc/status
 google.golang.org/grpc/balancer
+google.golang.org/grpc/balancer/base
 google.golang.org/grpc/balancer/roundrobin
+google.golang.org/grpc/binarylog/grpc_binarylog_v1
+google.golang.org/grpc/codes
 google.golang.org/grpc/connectivity
 google.golang.org/grpc/credentials
+google.golang.org/grpc/credentials/internal
 google.golang.org/grpc/encoding
 google.golang.org/grpc/encoding/proto
 google.golang.org/grpc/grpclog
@@ -163,8 +166,10 @@
 google.golang.org/grpc/internal/envconfig
 google.golang.org/grpc/internal/grpcrand
 google.golang.org/grpc/internal/grpcsync
+google.golang.org/grpc/internal/syscall
 google.golang.org/grpc/internal/transport
 google.golang.org/grpc/keepalive
+google.golang.org/grpc/metadata
 google.golang.org/grpc/naming
 google.golang.org/grpc/peer
 google.golang.org/grpc/resolver
@@ -172,11 +177,8 @@
 google.golang.org/grpc/resolver/passthrough
 google.golang.org/grpc/serviceconfig
 google.golang.org/grpc/stats
+google.golang.org/grpc/status
 google.golang.org/grpc/tap
-google.golang.org/grpc/balancer/base
-google.golang.org/grpc/credentials/internal
-google.golang.org/grpc/binarylog/grpc_binarylog_v1
-google.golang.org/grpc/internal/syscall
 # gopkg.in/jcmturner/aescts.v1 v1.0.1
 gopkg.in/jcmturner/aescts.v1
 # gopkg.in/jcmturner/dnsutils.v1 v1.0.1
@@ -186,32 +188,32 @@
 gopkg.in/jcmturner/gokrb5.v7/client
 gopkg.in/jcmturner/gokrb5.v7/config
 gopkg.in/jcmturner/gokrb5.v7/credentials
-gopkg.in/jcmturner/gokrb5.v7/gssapi
-gopkg.in/jcmturner/gokrb5.v7/iana/chksumtype
-gopkg.in/jcmturner/gokrb5.v7/iana/keyusage
-gopkg.in/jcmturner/gokrb5.v7/keytab
-gopkg.in/jcmturner/gokrb5.v7/messages
-gopkg.in/jcmturner/gokrb5.v7/types
 gopkg.in/jcmturner/gokrb5.v7/crypto
-gopkg.in/jcmturner/gokrb5.v7/crypto/etype
-gopkg.in/jcmturner/gokrb5.v7/iana/errorcode
-gopkg.in/jcmturner/gokrb5.v7/iana/flags
-gopkg.in/jcmturner/gokrb5.v7/iana/nametype
-gopkg.in/jcmturner/gokrb5.v7/iana/patype
-gopkg.in/jcmturner/gokrb5.v7/kadmin
-gopkg.in/jcmturner/gokrb5.v7/krberror
-gopkg.in/jcmturner/gokrb5.v7/iana/etypeID
-gopkg.in/jcmturner/gokrb5.v7/iana
-gopkg.in/jcmturner/gokrb5.v7/iana/adtype
-gopkg.in/jcmturner/gokrb5.v7/iana/asnAppTag
-gopkg.in/jcmturner/gokrb5.v7/iana/msgtype
-gopkg.in/jcmturner/gokrb5.v7/pac
-gopkg.in/jcmturner/gokrb5.v7/iana/addrtype
 gopkg.in/jcmturner/gokrb5.v7/crypto/common
+gopkg.in/jcmturner/gokrb5.v7/crypto/etype
 gopkg.in/jcmturner/gokrb5.v7/crypto/rfc3961
 gopkg.in/jcmturner/gokrb5.v7/crypto/rfc3962
 gopkg.in/jcmturner/gokrb5.v7/crypto/rfc4757
 gopkg.in/jcmturner/gokrb5.v7/crypto/rfc8009
+gopkg.in/jcmturner/gokrb5.v7/gssapi
+gopkg.in/jcmturner/gokrb5.v7/iana
+gopkg.in/jcmturner/gokrb5.v7/iana/addrtype
+gopkg.in/jcmturner/gokrb5.v7/iana/adtype
+gopkg.in/jcmturner/gokrb5.v7/iana/asnAppTag
+gopkg.in/jcmturner/gokrb5.v7/iana/chksumtype
+gopkg.in/jcmturner/gokrb5.v7/iana/errorcode
+gopkg.in/jcmturner/gokrb5.v7/iana/etypeID
+gopkg.in/jcmturner/gokrb5.v7/iana/flags
+gopkg.in/jcmturner/gokrb5.v7/iana/keyusage
+gopkg.in/jcmturner/gokrb5.v7/iana/msgtype
+gopkg.in/jcmturner/gokrb5.v7/iana/nametype
+gopkg.in/jcmturner/gokrb5.v7/iana/patype
+gopkg.in/jcmturner/gokrb5.v7/kadmin
+gopkg.in/jcmturner/gokrb5.v7/keytab
+gopkg.in/jcmturner/gokrb5.v7/krberror
+gopkg.in/jcmturner/gokrb5.v7/messages
+gopkg.in/jcmturner/gokrb5.v7/pac
+gopkg.in/jcmturner/gokrb5.v7/types
 # gopkg.in/jcmturner/rpc.v1 v1.1.0
 gopkg.in/jcmturner/rpc.v1/mstypes
 gopkg.in/jcmturner/rpc.v1/ndr