let circle detect versions required

bear · bear · commit 8152da4b2fba · 2016-05-26T02:58:27.000-04:00
diff --git a/circle.yml b/circle.yml
@@ -1,6 +1,3 @@
-machine:
-  python:
-      version: 2.7.11, 3.5.1
 
 dependencies:
   override:
