Add "testFramework" option

[Turbo87]

This PR adds a testFramework option that can be used to add either ember-cli-qunit or ember-cli-mocha to the package.json file of the project that is being tested.

see emberjs/data@master...Turbo87:mocha-blueprint-tests for an example of how to use this

resolves #27

[Turbo87]

this approach seems to have a problem:

• the qunit/mocha detection in ember-data is done by checking for ember-cli-mocha in this.project.addonPackages
• this.project.addonPackages will only list packages from the package.json if they are actually available in node_modules
• having ember-cli-qunit and ember-cli-mocha installed in parallel is causing problems

any ideas how to resolve this?

[Turbo87]

it looks like the problem can be solved by checking this.project.dependencies() instead of this.project.addonPackages, because the former one doesn't require packages to actually be installed

[Turbo87]

using just a testFramework option is rather restrictive and I've been thinking whether we should generalize this approach and offer a packages options instead:

    return generateAndDestroy(['model-test', 'foo'], {
      packages: {
        'ember-cli-qunit': { remove: true },
        'ember-cli-mocha': { version: '*', dev: true }
      },
      files: [{
        file: 'tests/unit/models/foo-test.js'
      }]
    });

[trabus]

using just a testFramework option is rather restrictive and I've been thinking whether we should generalize this approach and offer a packages options instead

I like the idea, though I think the generalization kind of obscures the purpose. I'm having trouble thinking of other specific uses atm, do you have any?

[trabus]

I'm having trouble thinking of other specific uses atm, do you have any?

Actually, I take that back. It could be used to test for conflicts with other packages that may affect an installed blueprint.

[Turbo87]

closing this in favor of #31