Revert "added statsmodels to dependencies for CI"

This reverts commit 7cf2ad0.

Author: emmanuelle

.circleci/create_conda_optional_env.sh

@@ -16,7 +16,7 @@ if [ ! -d $HOME/miniconda/envs/circle_optional ]; then
     # Create environment
     # PYTHON_VERSION=2.7 or 3.5
     $HOME/miniconda/bin/conda create -n circle_optional --yes python=$PYTHON_VERSION \
-requests nbformat six retrying psutil pandas decorator pytest mock nose poppler xarray scikit-image ipython jupyter ipykernel ipywidgets statsmodels
+requests nbformat six retrying psutil pandas decorator pytest mock nose poppler xarray scikit-image ipython jupyter ipykernel ipywidgets
 
     # Install orca into environment
     $HOME/miniconda/bin/conda install --yes -n circle_optional -c plotly plotly-orca==1.3.1

packages/python/plotly/tox.ini

@@ -59,7 +59,6 @@ deps=
     pytest==3.5.1
     pandas==0.24.2
     xarray==0.10.9
-    statsmodels==0.11.1
     backports.tempfile==1.0
     optional: --editable=file:///{toxinidir}/../plotly-geo
     optional: numpy==1.16.5