Upgrade Mocha dep and increase timeout

Travis can be slow and sometimes time out.
Don't save dependency to component.json when it doesn't resolve

Fixes the case when install is called with --save and the dependecy
is saved to component.json even if it wasn't resolved.
Remove links pointing to nonexistent folders on cache-clean, #182.
Add an init command that generates a component.json
Merge pull request #241 from wibblymat/issue-219

Add an init command that generates a component.json (Fixes #219)