First bit of tests

Added tests for the primary commands.
Added travis configuration file

Configured to test both node 0.8 and 0.10. Also includes the explicit
call to grab the latest npm so that 0.8 actually works.
Explicitly run tests in test directory

Travis doesn't seem to like the test command without specifying the
directory...
Update rather than install npm

Ensure that npm is updated rather than installing the
latest version over the existing version.
Another attempt and mocha without a Makefile

Make sure that the pathing is relative.
Added test directory back.

The test directory somehow ended up in the .gitignore. Tests have
been added back.
Updated preinstall and readme

Specify exact version of npm on preinstall and cleaned up readme. Also
added travis badge to readme.
Updates tests and styling

Updated to use a spy when testing exec, added version badge, and
made some changes to the styling of the module.

Also cleans up some of the output when running demeteorizer such as
the extra newline when checking the meteor version.
Updated releases in readme

Created legit releases and linked the release history to the releases
page.
Merge pull request #75 from onmodulus/feature/tests

Adds unit tests and lint