Update Swift to 3.1.1 used in Travis.
Update Swift to 3.1.1 used in Travis.

Swinject/Swinject,yoichitgy/Swinject,Swinject/Swinject,yoichitgy/Swinject,yoichitgy/Swinject,Swinject/Swinject,yoichitgy/Swinject,Swinject/Swinject