adding failing tests for elapsed time

#### Summary:

Adds a couple of tests that check for elapsed time being output to the correct locations.

#### Intended Effect:

Prevent this error from happening again.

#### How to Verify:

Run the unit tests added.

#### Side Effects:

This depends on stan-dev/stan#775. That needs to be merged first or this will fail to pass.

#### Documentation:

This fixes broken behavior. After the merge, this will match documentation.

#### Reviewer Suggestions:

Anyone.