Add initial version of unification monad transformer

Yes, it's in the same file as the syntax. Make it work,
make it right, make it fast.

spago.dhall

@@ -11,7 +11,20 @@ When creating a new Spago project, you can use
 to generate this file without the comments in this block.
 -}
 { name = "bergamot"
-, dependencies = [ "foldable-traversable", "lists", "logict", "prelude" ]
+, dependencies =
+  [ "bifunctors"
+  , "control"
+  , "foldable-traversable"
+  , "lazy"
+  , "lists"
+  , "logict"
+  , "maybe"
+  , "newtype"
+  , "ordered-collections"
+  , "prelude"
+  , "transformers"
+  , "tuples"
+  ]
 , packages = ./packages.dhall
 , sources = [ "src/**/*.purs", "test/**/*.purs" ]
 }