Refactor functors and related packages (#41)

This is part of a set of commits that rearrange the dependencies between
multiple packages. The immediate motivation is to allow certain newtypes
to be reused between `profunctor` and `bifunctors`, but this particular
approach goes a little beyond that in two ways: first, it attempts to
move data types (`either`, `tuple`) toward the bottom of the dependency
stack; and second, it tries to ensure no package comes between
`functors` and the packages most closely related to it, in order to open
the possibility of merging those packages together (which may be
desirable if at some point in the future additional newtypes are added
which reveal new and exciting constraints on the module dependency
graph).

CHANGELOG.md

@@ -7,8 +7,11 @@ Notable changes to this project are documented in this file. The format is based
 Breaking changes:
 - Added support for PureScript 0.14 and dropped support for all previous versions (#35)
 - Removed `Costrong` and `Cochoice` from `Costar` (#38)
+- `Clown`, `Costar`, `Cowrap`, and `Joker` have been moved to the `Data.Functors` module in the `purescript-functors` package, so that the same types can also be used as bifunctors; `Cowrap` was renamed to `Flip` (#41)
+- `Wrap` was deleted; it is expected that any instances of `Profunctor` will be accompanied by a corresponding instance of `Functor` (#41)
 
 New features:
+- This package no longer depends on the `purescript-contravariant` package (#41)
 
 Bugfixes:
 

bower.json

@@ -21,7 +21,6 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-contravariant": "master",
     "purescript-control": "master",
     "purescript-distributive": "master",
     "purescript-either": "master",