Run "go generate" when GO_TEST_GENERATE is defined

ci.yml

@@ -3,6 +3,7 @@ go_test:
   image: registry.git.autistici.org/ai3/docker/test/golang:master
   script:
     - if [ -n "$GO_TEST_PACKAGES" ]; then apt-get -q update; env DEBIAN_FRONTEND=noninteractive apt-get -qy install --no-install-recommends $GO_TEST_PACKAGES; fi
+    - if [ -n "$GO_TEST_GENERATE" ]; then go generate ./... ; fi
     - run-go-test ${GO_TEST_ARGS:-} ./...
   coverage: '/overall coverage: \d+.\d+%/'
   artifacts: