Release depends on generated proto code (#95)

Since the googleapis Status files were removed from source control (and
are created using 'make generate'), we need to update the release
workflow to run generate prior to releasing code.

Makefile

@@ -110,7 +110,7 @@ lintfix: # Applies the lint changes.
 	./gradlew $(GRADLE_ARGS) spotlessApply
 
 .PHONY: release
-release: ## Upload artifacts to Sonatype Nexus.
+release: generate ## Upload artifacts to Sonatype Nexus.
 	./gradlew $(GRADLE_ARGS) --info publish --stacktrace --no-daemon --no-parallel
 	./gradlew $(GRADLE_ARGS) --info closeAndReleaseRepository