0.10.0

Non-breaking changes:

• Changed from fold to for in which resulted in a average 10-20% boost in
  performance for all castings using the case module.

Fixes:

• Fixed issue with snake case like strings where numbers were incorrectly
  permitted to be next to a string e.g. string1 was considered valid when it
  should have been string_1. This has been corrected as part of the above
  change.

Why is this not 0.9.1?

• The change in this case are all on private API. This normally wouldn't cause a
  breaking change as there are extensive tests wrapping all methods. This
  however doesn't preclude an edge case that hasn't been considered. I've
  deemed it safer to call this a 0.x.0 release for that reason.