document test_go_test make target

License: MIT
Signed-off-by: Steven Allen <steven@stebalien.com>

Rules.mk

@@ -145,7 +145,8 @@ help:
 	@echo '  test                    - Run all tests'
 	@echo '  test_short              - Run short go tests and short sharness tests'
 	@echo '  test_go_short           - Run short go tests'
-	@echo '  test_go_expensive       - Run all go tests (and test build)'
+	@echo '  test_go_test            - Run all go tests'
+	@echo '  test_go_expensive       - Run all go tests and compile on all platforms'
 	@echo '  test_go_race            - Run go tests with the race detector enabled'
 	@echo '  test_go_megacheck       - Run the `megacheck` vetting tool'
 	@echo '  test_sharness_short     - Run short sharness tests'