Enhancement: Add Makefile

Closes GH-621.

.editorconfig

@@ -8,3 +8,9 @@ charset = utf-8
 indent_size = 2
 indent_style = space
 trim_trailing_whitespace = true
+
+[Makefile]
+charset = utf-8
+indent_size = 4
+indent_style = tab
+trim_trailing_whitespace = true

.github/CONTRIBUTING.md

@@ -63,7 +63,7 @@ about what you're working on, you can contact us via the
 - Run
 
   ```
-  php tests/run-tests.php -q --show-diff
+  make tests
   ```
 
   to check your change doesn't break other features.
@@ -118,7 +118,7 @@ Having said that, here are the organizational rules:
 5. Test your changes before committing them. We mean it. Really. To do so use
 
    ```
-   php tests/run-tests.php -q --show-diff
+   make tests
    ```
 
 6. Use reasonable commit messages.

Makefile

@@ -0,0 +1,7 @@
+.PHONY: help
+help: ## Displays this list of targets with descriptions
+	@grep -E '^[a-zA-Z0-9_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[32m%-30s\033[0m %s\n", $$1, $$2}'
+
+.PHONY: tests
+tests: ## Runs tests
+	php tests/run-tests.php -j3 -q