Revert "Add specific check for "require" in hasModule check (fixes bug when using with QUnit)."

This reverts commit ed6a2d4e1f3e32abce6939ef451f0cd4f8c54a1b.
This was discussed in https://github.com/moment/moment/issues/1537#issuecomment-39505749
Merge pull request #1588 from ichernev/fix-cjs-exporting

Revert "Add specific check for "require" in hasModule check"