Small dev. changes [.gitignore, package.json, .editorconfig, .jsbeautifyrc]

[alundiak]

1. Even, require-css doesn't have devDependencies (so far, maybe in future something changed), we better to ignore node_modules and bower_components. This is valuable at least for use case, mentioned in README.md file in regards to installing csso locally and running npm test which requires local requirejs. Also ignored DS_Strore and .log

2. During command r.js -o example/build.js it's also checking node_modules and bower_components folders, if such exists. So I added to exclude pattern in example/build.js.

3. npm has dedicated script test, which can be valuable during CI, and just for simplification and usability as developer not to type lot of text. Added alias in package.json.
   But FYI: for running node test/test.js u need to install requirejs locally, because global is not accessible. In regards to this small note, I may create separate PR later.

4. bower.json has not valid structure, which cause warning during any bower activity:

bower invalid-meta for:/Users/alund/prj/require-css/bower.json
bower invalid-meta The "main" field has to contain only 1 file per filetype; found multiple .js files: ["css.js","css-builder.js","normalize.js"]

So I changed to be only css.js

5. I personally like to use tab spacing, but I see, that majority of code is indented by using 2 spaces. So I added .editorconfig and .jsbeautifyrc which will prevent from wrong indentation. Also in future, I will create grunt task for auto-jsbeautify before commit.

[alundiak]

trim_trailing_whitespace = true will be removed. It's not very useful.

[alundiak]

In many cases, this insert_final_newline = true expected by github, so better to have it automated.