Remove direct dependency on multipledispatch

It's only a transitive dependency via etuples and logical-unification.

Author: maresb

README.md

@@ -149,7 +149,7 @@ We can express the grandfather relationship as a distinct relation by creating a
 
 ## Extending `kanren`
 
-`kanren` uses [`multipledispatch`](http://github.com/mrocklin/multipledispatch/) and the [`logical-unification` library](https://github.com/pythological/unification) to support pattern matching on user defined types.  Essentially, types that can be unified can be used with most `kanren` goals.  See the [`logical-unification` project's examples](https://github.com/pythological/unification#examples) for demonstrations of how arbitrary types can be made unifiable.
+`kanren` uses the [`logical-unification` library](https://github.com/pythological/unification) to support pattern matching on user defined types.  Essentially, types that can be unified can be used with most `kanren` goals.  See the [`logical-unification` project's examples](https://github.com/pythological/unification#examples) for demonstrations of how arbitrary types can be made unifiable.
 
 ## About
 

pyproject.toml

@@ -29,7 +29,6 @@ dependencies = [
     "cons >= 0.4.0",
     "etuples >= 0.3.1",
     "logical-unification >= 0.4.1",
-    "multipledispatch",
     "toolz",
     "typing_extensions",
 ]