Added option to use jasmine_node instead of mochaTest

I prefer to use Jasmine for the server-side testing, as it means the server-side and client-side tests can all be written with the same test runner, using the same syntax. So I included an option in the generator to ask if the user would prefer mocha or jasmine.

It defaults to mocha, which would work as the generator does today, but if the user chooses `j` for jasmine, the generator will install and setup [jasmine_node](https://github.com/mhevery/jasmine-node) specs instead. Running `grunt test` will use the [grunt-jasmine-node](https://github.com/jasmine-contrib/grunt-jasmine-node) task instead of `mochaTest`.

I've also added some useful jasmine matchers that can be included server or client side. There needs to be a manual changing of the `karma.conf` file in order to use these client side, as they need to be added to the `files` array and this isn't possible at generation-time when invoking the karma generator.