Revert Dist::Zilla support

Reverts commits c4428b44a22b2f4913dcc50fc44a3ba40714b50d,
e15fbd6414fcef9e56ff3ce5ebd63ab4ee416372 and
fac9e4feee0184a7cebd24565c6d1faccc3e4aee.

See #95 for reasoning.