ok switch to py3 test only

Author: computron

.circleci/config.yml

@@ -4,7 +4,7 @@ jobs:
   py3test:
     working_directory: ~/fireworks
     docker:
-      - image: materialsvirtuallab/circle-ci-pmg-py3:3.7.3
+      - image: continuumio/miniconda3:4.6.14
       - image: circleci/mongo:latest
     steps:
       - checkout
@@ -57,4 +57,4 @@ workflows:
   version: 2
   build_and_test:
     jobs:
-      - py2test
+      - py3test