Remove deprecation warnings in tests (#12686)

dstansby · timhoffm · commit 8a7666d3dca5 · 2018-11-01T00:27:31.000+01:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -1,4 +1,4 @@
-import collections
+import collections.abc
 import functools
 import itertools
 import logging
@@ -4187,7 +4187,7 @@ def scatter(self, x, y, s=None, c=None, marker=None, cmap=None, norm=None,
         if (c_none or
                 co is not None or
                 isinstance(c, str) or
-                (isinstance(c, collections.Iterable) and
+                (isinstance(c, collections.abc.Iterable) and
                     isinstance(c[0], str))):
             c_array = None
         else:
