Fix regression for issue #1526 regarding onFirstCall().throws()

[noisecapella]

Purpose (TL;DR) - mandatory

Fix #1526 by adding exceptionCreator to the list of fields checked in isPresent

Background (Problem in detail) - optional

The PR #1511 broke this behavior because it added exceptionCreator as a field which stored a function which would create the exception.

Solution - optional

The check was added in isPresent so that the behavior is detected as being set.

How to verify - mandatory

If you run the new test on master it should fail, and it should pass on this branch.

Checklist for author

• npm run lint passes
• References to standard library functions are cached.

[fatso83]

Thanks! Manually verified too.

[mroderick]

Thank you :)

[mroderick]

This was released with sinon@3.2.1