Revert "_.partition only accepts arrays."

This reverts commit e4785d38556632d58334616c33292eee95fddfb3.
Merge pull request #1479 from braddunbar/partition

Revert "_.partition only accepts arrays."
Documentation: clarify the functionality of _.defaults for multiple defaults objects within the same call.
Defaults documentation update: taylor can't spell.
Fix bower command typo in docs
Merge pull request #1484 from ameralimanovic/fix-typo-bower

Fix bower command typo in docs
Merge pull request #1481 from jtfairbank/master

Documentation: clarify the functionality of _.defaults for multiple defaults objects within the same call.
Add a note about `_.keys` to the changelog.
Merge pull request #1490 from braddunbar/keys

Add a note about `_.keys` to the changelog.