Adding better errors when passing null or undefined to modifiers

[kiwiupover]

• Asserts an error then the function passed to did-insert, did-update and will-destroy is not a function.

• Today the error is fn must be a function fn has another meaning in emberland.

Upgrading ember-resolver fixes the test failures of ember-release, ember-beta, and ember-canary.

Canary is failing due to using Ember. I have an follow up PR that updates ember and ember-cli that will fix this issue.

I have added allow failure for ember-canary due to the failure above.

Here is this same PR running on my github so we can run the tests all the tests are passing except the ember-canary which we know is failing.

https://github.com/kiwiupover/ember-render-modifiers/pull/4

[RobbieTheWagner]

@kiwiupover thanks for the PR! Would you mind rebasing to latest master please?