Remove unused dependencies

[Turbo87]

We don't publish the dummy app, so we don't need all of these addons.

[stefanpenner]

not ok 8 Chrome 71.0 - [2 ms] - ember-resolver/resolvers/classic: can access at deprecated 'resolver' module name
    ---
        actual: >
            null
        stack: >
            Error: Could not find module `ember` imported from `resolver`
                at missingModule (http://localhost:7357/assets/vendor.js:252:11)
                at findModule (http://localhost:7357/assets/vendor.js:263:7)
                at Module.findDeps (http://localhost:7357/assets/vendor.js:173:24)
                at findModule (http://localhost:7357/assets/vendor.js:267:11)
                at requireModule (http://localhost:7357/assets/vendor.js:29:15)
                at r (http://localhost:7357/assets/vendor.js:181:14)
                at Object.<anonymous> (http://localhost:7357/assets/tests.js:197:47)
                at runTest (http://localhost:7357/assets/test-support.js:4226:30)
                at Test.run (http://localhost:7357/assets/test-support.js:4212:6)
                at http://localhost:7357/assets/test-support.js:4433:12

[Turbo87]

@stefanpenner see #295