Adding vtk install to tests.

tests/regression_tests/plot/test.py

@@ -53,8 +53,12 @@ class PlotTestHarness(TestHarness):
         outstr = sha512.hexdigest()
 
         # test the voxel to vtk conversion script
-        call(['../../../scripts/openmc-voxel-to-vtk'] +
-             glob.glob('plot_4.h5'))
+        try:
+            import vtk
+            call(['../../../scripts/openmc-voxel-to-vtk'] +
+                 glob.glob('plot_4.h5'))
+        except:
+            pass
 
         return outstr
 

tools/ci/travis-install.sh

@@ -26,5 +26,10 @@ python tools/ci/travis-install.py
 # Install Python API in editable mode
 pip install -e .[test]
 
+a=$(dpkg --compare-versions $(python --version | cut -d" " -f 2) lt 3.7.0)
+if [ $a -eq 0 ]; then
+    pip install -e .[vtk]
+fi
+
 # For uploading to coveralls
 pip install coveralls