VOL-1460 Updated core to use voltha-protos instead of local protos
Moved protos to python directory in order to maintain functionaly of containers built there.
Added capability to do local builds of protos
Added instructions on running dep ensure for getting protos.
Updated github.com/golang/protobuf version to v1.3.1

Change-Id: Ia6ef55f07f0d5dcb5b750d7c37b21b71db85bfc4
diff --git a/vendor/github.com/golang/protobuf/ptypes/duration/duration.pb.go b/vendor/github.com/golang/protobuf/ptypes/duration/duration.pb.go
index a7beb2c..0d681ee 100644
--- a/vendor/github.com/golang/protobuf/ptypes/duration/duration.pb.go
+++ b/vendor/github.com/golang/protobuf/ptypes/duration/duration.pb.go
@@ -1,11 +1,13 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // source: google/protobuf/duration.proto
 
-package duration // import "github.com/golang/protobuf/ptypes/duration"
+package duration
 
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	math "math"
+)
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ = proto.Marshal
@@ -16,7 +18,7 @@
 // is compatible with the proto package it is being compiled against.
 // A compilation error at this line likely means your copy of the
 // proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
 
 // A Duration represents a signed, fixed-length span of time represented
 // as a count of seconds and fractions of seconds at nanosecond
@@ -99,17 +101,19 @@
 func (m *Duration) String() string { return proto.CompactTextString(m) }
 func (*Duration) ProtoMessage()    {}
 func (*Duration) Descriptor() ([]byte, []int) {
-	return fileDescriptor_duration_e7d612259e3f0613, []int{0}
+	return fileDescriptor_23597b2ebd7ac6c5, []int{0}
 }
+
 func (*Duration) XXX_WellKnownType() string { return "Duration" }
+
 func (m *Duration) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Duration.Unmarshal(m, b)
 }
 func (m *Duration) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Duration.Marshal(b, m, deterministic)
 }
-func (dst *Duration) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Duration.Merge(dst, src)
+func (m *Duration) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Duration.Merge(m, src)
 }
 func (m *Duration) XXX_Size() int {
 	return xxx_messageInfo_Duration.Size(m)
@@ -138,11 +142,9 @@
 	proto.RegisterType((*Duration)(nil), "google.protobuf.Duration")
 }
 
-func init() {
-	proto.RegisterFile("google/protobuf/duration.proto", fileDescriptor_duration_e7d612259e3f0613)
-}
+func init() { proto.RegisterFile("google/protobuf/duration.proto", fileDescriptor_23597b2ebd7ac6c5) }
 
-var fileDescriptor_duration_e7d612259e3f0613 = []byte{
+var fileDescriptor_23597b2ebd7ac6c5 = []byte{
 	// 190 bytes of a gzipped FileDescriptorProto
 	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x92, 0x4b, 0xcf, 0xcf, 0x4f,
 	0xcf, 0x49, 0xd5, 0x2f, 0x28, 0xca, 0x2f, 0xc9, 0x4f, 0x2a, 0x4d, 0xd3, 0x4f, 0x29, 0x2d, 0x4a,