FIX add scikit-learn to circle.yml

Author: mfeurer

circle.yml

@@ -24,7 +24,7 @@ dependencies:
     # install numpy first as it is a compile time dependency for other packages
     - pip install --upgrade numpy
     # install documentation building dependencies
-    - pip install --upgrade matplotlib setuptools nose coverage sphinx pillow sphinx-gallery sphinx_bootstrap_theme cython numpydoc
+    - pip install --upgrade matplotlib setuptools nose coverage sphinx pillow sphinx-gallery sphinx_bootstrap_theme cython numpydoc scikit-learn
     # Installing required packages for `make -C doc check command` to work.
     - sudo -E apt-get -yq update
     - sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install dvipng texlive-latex-base texlive-latex-extra
@@ -54,4 +54,4 @@ general:
   # Restric the build to the branch master only
   branches:
     only:
-       - develop
+       - develop