Type annotations on binders incorrectly highlighted

``` purescript
example = do
  n :: Int <- get
  put (n + 1)
```

(In Atom the `get` and the rest of the line are highlighted like a top level type definition)

I'd expect nothing on the variable, the rest of the line to be highlighted as normal, the type to be highlighted as a type as in a top level definition.

In fact it seems that inline type annotations are also not highlighted as types.
