Move common to evaluate.utils.

jedi/evaluate/finder.py

@@ -18,7 +18,7 @@ check for -> a is a string). There's big potential in these checks.
 from parso.python import tree
 from parso.tree import search_ancestor
 from jedi import debug
-from jedi.common import unite
+from jedi.evaluate.utils import unite
 from jedi import settings
 from jedi.evaluate import representation as er
 from jedi.evaluate.instance import AbstractInstanceContext