Fixed linting module import issues

Upstream published go module for golint had issues and since we don't
want to hardcode this in the go.mod file, we now specify the override in
the style_checker itself.

golang/lint#397

bin/check_style

@@ -49,7 +49,9 @@ style_errs=$(docker run \
   --rm \
   secretless-dev \
   bash -ec "
-    go get -u golang.org/x/lint/golint
+    # https://github.com/golang/lint/issues/397
+    go get golang.org/x/lint@v0.0.0-20180702182130-06c8688daad
+    go get golang.org/x/lint/golint
     golint ${PROJECT_ROOT}cmd/...
     golint ${PROJECT_ROOT}internal/...
     golint ${PROJECT_ROOT}pkg/...