Update astropy-helpers to v2.0

bsipocz · bsipocz · commit a75ff85efbd4 · 2017-07-06T16:54:45.000+01:00
diff --git a/astropy_helpers b/astropy_helpers
@@ -1 +1 @@
-Subproject commit 5abc0f82e640261f17646ae50be1546f9e3d8e8d
+Subproject commit ed2e7897862ae9e979b336df670d7a5541cdd8f0
