enabled dependency of jekyll 2.0 or later
Merge pull request #22 from hsbt/upgrade-jekyll2

Enabled dependency of jekyll 2.0
Now config can be also specified as an options to jekyll
Set proper jekyll, and rack versions allowed.
Updated .gitignore to follter .ruby-version, and .ruby-gemset files
Merge pull request #25 from majioa/majioa

Allowed option :config, and jekyll version more than 2
First pass at showing a wait page during rendering.
Allow user to configure wait page.
Add a nicely styled default wait page.
Add documentation about :wait_page option.