go back to using 2.8 (2.9 no longer required)

Author: BRONSOLO

circle.yml

@@ -4,7 +4,7 @@ machine:
 
     PLOTLY_PACKAGE_ROOT: /home/ubuntu/${CIRCLE_PROJECT_REPONAME}
     PLOTLY_CONFIG_DIR: ${HOME}/.plotly
-    PLOTLY_PYTHON_VERSIONS: 2.7.10 3.3.3 3.4.1
+    PLOTLY_PYTHON_VERSIONS: 2.7.8 3.3.3 3.4.1
     PLOTLY_CORE_REQUIREMENTS_FILE: ${PLOTLY_PACKAGE_ROOT}/requirements.txt
     PLOTLY_OPTIONAL_REQUIREMENTS_FILE: ${PLOTLY_PACKAGE_ROOT}/optional-requirements.txt