Makefile: use --tags in git describe so lightweight tags resolve

Signed-off-by: Tamal Saha <tamal@appscode.com>

Author: tamalsaha

Makefile

@@ -26,7 +26,7 @@ API_GROUPS           ?= appcatalog:v1alpha1 metrics:v1alpha1
 
 # This version-strategy uses git tags to set the version string
 git_branch       := $(shell git rev-parse --abbrev-ref HEAD)
-git_tag          := $(shell git describe --exact-match --abbrev=0 2>/dev/null || echo "")
+git_tag          := $(shell git describe --tags --exact-match --abbrev=0 2>/dev/null || echo "")
 commit_hash      := $(shell git rev-parse --verify HEAD)
 commit_timestamp := $(shell date --date="@$$(git show -s --format=%ct)" --utc +%FT%T)