Remove whitespace from Cheffile in integration tests
Support :librarian option in `solo bootstrap`

PR #180 added `--no-librarian` option to the cook command. If the
bootstrap command does not know about the key, the value will be set to nil
thus disabling `librarian-chef install`. This fixes it (and integration
tests.)
Extract `base` to instance variable

Reduce the need to pass it around for all methods.
Generate Cheffile on `init` if specified
Add class for adding entries to .gitignore
Add Librarian specific entries to .gitignore on `init`
Merge pull request #182 from tmatilai/init-librarian

Generate Cheffile and .gitignore on `knife solo init --librarian`