Update dependencies

- Update retext-visit, retext, retext-content;
- Remove retext from peer dependencies.
Refactor spec
Remove testling
Fix property order in component.json, package.json, bower.json
Update Installation in docs

- Add Bower as an installation method;
- Rename Component.js > Component;
- Fix casing of NPM > npm.
Update .gitignore, .npmignore
Remove browser test
Refactor API
Refactor Readme.md
Update changelog for 0.1.1
0.1.1