update docker version in circle

Author: oesteban

circle.yml

@@ -1,10 +1,12 @@
 machine:
+  pre:
+    - sudo curl -L -o /usr/bin/docker 'https://s3-external-1.amazonaws.com/circle-downloads/docker-1.9.1-circleci'
+    - sudo chmod 0755 /usr/bin/docker
   environment:
     OSF_NIPYPE_URL: "https://files.osf.io/v1/resources/nefdp/providers/osfstorage"
     DATA_NIPYPE_TUTORIAL_URL: "${OSF_NIPYPE_URL}/57f4739cb83f6901ed94bf21"
     DATA_NIPYPE_FSL_COURSE: "${OSF_NIPYPE_URL}/57f472cf9ad5a101f977ecfe"
     DATA_NIPYPE_FSL_FEEDS: "${OSF_NIPYPE_URL}/57f473066c613b01f113e7af"
-
   services:
     - docker