Update to Maruku 0.7.0, fix tests

I do not believe there's been any major API change, AFAIK

[Maruku Changelog](http://rdoc.info/github/bhollis/maruku/master/file/CHANGELOG.md)

Gemspec now asks for 0.7.0 (final), which has been released.

It has changed some output behaviour after transitioning to its own output engine.

The parser will now do a `.strip` to take out any newlines Maruku has added surrounding html produced.

It now produces `"` for attribute quotes and uses the !CDATA tag inside script so that it will produce valid XHTML.

I updated the tests to account for these.

I also rebased on top of master, I assume this is wanted.

See #1558 

If you would like to submit this to master instead, I can do so.