Update CHANGELOG.md for CocoaPods/Core#30

[Changelog]

Going to miss the Appie endorsement… 🐶

Closes #1462

See #1450

Closes #1454

Fixed a crash which was causing a failure in `pod lib create` if the name of
the Pod included spaces. As spaces are not supported now this is gracefully
handled with an informative message.

Fixes #1456

Closes #1420