Removed mark2 support from the cookbook.

Upstream has declared mark2 as "on life-support" so it was decided
to no longer support it.

Read more here:

http://www.reddit.com/r/admincraft/comments/1s1t4e/the_state_of_mark2_and_the_path_forward/

This also bumps minecraft to 1.7.4 now that we are not waiting on
mark2 bugs to be fixed.
use ubuntu cookbook for tests on ubuntu
stable test-kitchen and add kitchen-vagrant
bump attributes for 1.7.5
bump version for 1.7.5 changes
Merge pull request #28 from webframp/master

Minor changes for minecraft 1.7.5
Replace Strainer with a Rakefile, @sethvargo has mentioned Strainer will be going away.
Clean up kitchen.yml
Remove bounds check while rendering configuration files.

While this could prevent some errors I believe it's mostly a useless
check. We want a error if the template or attribute is
missing This would cause creation of files to silently fail. If I'm
missing the usefulness here slap me.
Finally, we have chefspec!
Update the Changelog
Prepare for release
Bump ruby version
Use the 2.0 beta for stove
Version bump to 0.5.1 (for development)
Tweak stove settings for the next time around