DEV: Cleanup unused config files (#8515)

- codeclimate is not used for this repository
- .env.sample was added for Heroku deployment, which is no longer supported

.codeclimate.yml

@@ -1,21 +0,0 @@
-languages:
-   Ruby: true
-   JavaScript: true
-   Python: false
-   PHP: false
-
-exclude_paths:
- - "app/assets/javascripts/defer/*"
- - "app/assets/javascripts/ember-addons/*"
- - "lib/autospec/*"
- - "lib/es6_module_transpiler/*"
- - "lib/highlight_js/*"
- - "lib/import/*"
- - "lib/javascripts/*"
- - "lib/tasks/*"
- - "lib/*.js"
- - "public/*"
- - "script/*"
- - "spec/*"
- - "test/*"
- - "vendor/*"

.env.sample

@@ -1 +0,0 @@
-RAILS_ENV=development