Add scikit-image as optional dependency for continuous integration

Author: larrybradley

.continuous-integration/travis/setup_dependencies_common.sh

@@ -30,7 +30,7 @@ $CONDA_INSTALL pytest Cython jinja2 psutil
 # OPTIONAL DEPENDENCIES
 if $OPTIONAL_DEPS
 then
-  $CONDA_INSTALL scipy h5py matplotlib pyyaml
+  $CONDA_INSTALL scipy h5py matplotlib pyyaml scikit-image
   pip install beautifulsoup4
 fi
 

appveyor.yml

@@ -41,7 +41,7 @@ install:
     - "python --version"
 
     # Install specified version of numpy and dependencies
-    - "conda install -q --yes numpy=%NUMPY_VERSION% pytest Cython scipy h5py beautiful-soup jinja2 pyyaml"
+    - "conda install -q --yes numpy=%NUMPY_VERSION% pytest Cython scipy h5py beautiful-soup jinja2 pyyaml scikit-image"
 
 # Not a .NET project, we build SunPy in the install step instead
 build: false