Added the timeout option to the Mocha grunt task; set to 10000.
Removed the individual test suite timeouts, for all server tests.
Also, added global timeout for Mocha gulp task.
Added a timeout of 10000 ms to each server test file. This is an attempt
to solve the timeout issues that we're experiencing with the Mocha
tests. Especially, this is hoping to address the build fails that are
caused by such timeouts.
Issue is described in https://github.com/meanjs/mean/issues/955
