Added a make targets 'lint-style', 'lint-sanity', 'lint', and 'test'.

'lint-style' scans go files for formatting errors using 'gofmt'.
'lint-sanity' checks for common issues using 'go vet'.
'lint' is shorthand for 'lint-style' & 'lint-sanity'
'test' runs any existing tests using 'go test', and generates junit & coverage reports into tests/results/.

Change-Id: If0576180b5ca400280631a0583c1887ec9c61ccc
diff --git a/.gitignore b/.gitignore
index dba4360..fe90ae8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -61,6 +61,9 @@
 
 python/local_imports/**/*
 
+# test output
+tests/results
+
 # ignore uneeded items in vendor folders
 vendor/github.com/opencord/voltha-protos/protos
 vendor/github.com/opencord/voltha-protos/python