[chore] Release 4.0.1 (firebase#434)

[chore] Release 4.0.0 (firebase#415)

Bumped version to 3.2.1 (firebase#374)

Bumped version to 3.2.0 (firebase#366)

Bumped version to 3.1.0 (firebase#358)

Bumped version to 3.0.0 (firebase#344)

Bumped version to 2.18.0 (firebase#333)

* Bumped version to 2.18.0

* Removing extra whitespace

Bumped version to 2.17.0 (firebase#292)

* Bumped version to 2.17.0

* Removed additional whitespace

Bumped version to 2.16.0 (firebase#265)

Bumped version to 2.15.1 (firebase#253)