Update ember-test-helpers to expose pauseTest / resumeTest

[rwjblue]

• Update to v0.7.0-beta.9
• Re-export the importable helpers resumeTest and pauseTest
• Wrap this.pauseTest to properly reset the test timeout (to avoid the
  test from being marked as failed due to timing out while interacting).

Fixes #287

[azhiv]

this.pauseTest doesn't reset the timeout for me
It looks like assert.timeout(-1) doesn't do the thing when placed inside the body of pauseTest. However the workaround is to manually insert this statement in the beginning of your test. I suppose it has some peculiarities while executing in-between async/awaits and the execution time of an asynchronous test cannot be configured from inside the asynchronous context. It can only be executed in the beginning of the test while the context is synchronous.
My point is that the statement assert.timeout(-1) is useless and its comment is misleading. Any thoughts?

UPD: this.pauseTest works as expected in devmode

[rwjblue]

@azhiv - Would you mind making an issue so we can follow up on this? I agree, we need to rework things a bit...