Adds tests to ensure that all pre-1.0 package versions are locked

Let me know if the tests should be more thorough. I'm not checking for ranges, just for the use of `^` or `~`, but that seems to be how we specify all dependencies in ember-cli.
@brzpegasus - You can check to see if the thing is a range via:

```javascript
var isRange = /^[0-9.]+$/;

if (isRange.test(deps[name])) {
  assert(semver.gtr('1.0.0', deps[name]), '"' + name + '" has a valid version');
}
```

I'm just spit-ballin' at this point though.