Added .editorconfig to tell others about spaces and tabs

Also:
- formated source code according to these rules;
- added spaces after commas in test code

See GitHub issue #101

composer.json

@@ -13,7 +13,9 @@
         }
     ],
     "autoload": {
-        "classmap": ["."]
+        "classmap": [
+            "."
+        ]
     },
     "require-dev": {
         "phpunit/phpunit": "4.1.*"