Add stickler-ci configuration.
Add stickler-ci configuration.

In talking with @josegonzalez, stickler-ci.com helps reduce the amount of
time maintainers spend reviewing code by automatically giving style
feedback as pull request comments.

I've added linters for shell scripts and go files based on the linting
I could find in the existing make files.

claytonbrown/dokku,elia/dokku,jimjag/dokku,claytonbrown/dokku,progrium/dokku,alexquick/dokku,claytonbrown/dokku,progrium/dokku,progrium/dokku,dokku/dokku,dokku/dokku,alexquick/dokku,elia/dokku,elia/dokku,jimjag/dokku,jimjag/dokku,alexquick/dokku,alexquick/dokku,elia/dokku,dokku/dokku,claytonbrown/dokku,progrium/dokku,elia/dokku,progrium/dokku,progrium/dokku,alexquick/dokku,alexquick/dokku,progrium/dokku,elia/dokku,claytonbrown/dokku,jimjag/dokku,jimjag/dokku,dokku/dokku,elia/dokku,elia/dokku,dokku/dokku,dokku/dokku,claytonbrown/dokku,jimjag/dokku,alexquick/dokku,dokku/dokku,dokku/dokku,claytonbrown/dokku,jimjag/dokku,claytonbrown/dokku,progrium/dokku,jimjag/dokku,alexquick/dokku