Add make release and instructions

.github/CONTRIBUTING.md

@@ -34,4 +34,10 @@ I don't want to be too dogmatic about this, but here are some general things I t
 * Test are defined in `<package>_test` packages to ensure only the public interface is tested
 * If you export something, make sure you add appropriate godoc comments
 
+## Tagging a Release
+
+* Set the `Version` in _version.go_
+* Update CHANGELOG.md with the relevant changes
+* `make release` - will commit everything, create a tag and push
+
 [retool]: https://github.com/twitchtv/retool

Makefile

@@ -1,4 +1,6 @@
-.PHONY: bench setup test
+.PHONY: bench release setup test
+
+VERSION = $(shell cat version.go | sed -n 's/.*const Version = "\(.*\)"/\1/p')
 
 setup:
 	$(info Synching dev tools and dependencies...)
@@ -18,3 +20,10 @@ test: fixtures/fileset.pb
 
 test-ci: fixtures/fileset.pb bench
 	@retool do goverage -race -coverprofile=coverage.txt -covermode=atomic ./ ./utils
+
+release:
+	@echo Releasing v${VERSION}...
+	git add CHANGELOG.md version.go
+	git commit -m "Bump version to v${VERSION}"
+	git tag -m "Version ${VERSION}" "v${VERSION}"
+	git push && git push --tags

version.go

@@ -0,0 +1,4 @@
+package protokit
+
+// Version describes the current version of protokit being used
+const Version = "0.1.0-pre"