0.4.0-alpha: Merge pull request #3 from tarunon/swift4

Swift 4 support

0.3.0

Rename EnumX -> AnyEnumX
Add unwrap operator while every cases has same type.
Add mapK operator (K is 0..<X)

0.2.0

Support 6 or more case enums through environment variable.

0.1.0

initial commit