Enhance `make fmt` to cover running gci for golangci-lint compat (#515)

* Enhance `make fmt` to cover running gci for golangci-lint compat

I have been using `make fmt` for formatting code before submitting a pull request. It turned out not to work in some cases where you added a new import because the default go-fmt obviously do not organize imports as the golangci-lint and gci expect.
This fixes that, by adding a gci command to the `make fmt` target.
Please note that this does not cover installing gci. If you need, please submit another pull request to add something like a `make install-gci` and make the `make fmt` depenedent on that target, so that one can get automatic gci installation when running `make fmt` for first time.

Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>

* We don't need running gci via make on CI as we already run it as part of golangci-lint run

Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>

Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>

.github/workflows/ci.yaml

@@ -34,7 +34,7 @@ jobs:
     - name: Build
       run: make build build-test-tools
     - name: Test
-      run: make check pristine test
+      run: make check test
 
     - name: Prepare tar to upload built binaries
       run: tar -cvf built-binaries.tar helmfile diff-yamls yamldiff

Makefile

@@ -31,6 +31,7 @@ generate:
 
 fmt:
 	go fmt ${PKGS}
+	gci write --skip-generated -s standard -s default -s 'prefix(github.com/helmfile/helmfile)' .
 .PHONY: fmt
 
 check: