Adding recommonmark for build

Author: ajdapretnar

appveyor.yml

@@ -18,7 +18,7 @@ environment:
     # disable threaded builds on Python 3.5+ when using numpy's distutils
     # (https://github.com/numpy/numpy/issues/7607)
     BUILD_GLOBAL_OPTIONS: build -j1
-    BUILD_ENV: wheel==0.29.0 pip==9.0.1 numpy==1.9.3 sphinx==1.8.2
+    BUILD_ENV: wheel==0.29.0 pip==9.0.1 numpy==1.9.3 -r requirements-doc.txt
     # SIP 4.19.4+ with PyQt5==5.9.1+ segfault our tests (GH-2756)
     TEST_ENV: sip==4.19.6 PyQt5==5.9.2 numpy~=1.14.0 scipy~=1.0.0 scikit-learn pandas==0.21.1
 

requirements-dev.txt

@@ -1,4 +1,5 @@
 pylint
 radon
 # for build_htmlhelp command
-sphinx>=1.5
+sphinx>=1.5
+recommonmark

requirements-doc.txt

@@ -1,4 +1,5 @@
 docutils
 numpydoc
 Sphinx>=1.3
+recommonmark
 PyQt5

setup.py

@@ -17,7 +17,10 @@
 
 
 try:
+    # need sphinx and recommonmark for build_htmlhelp command
     from sphinx.setup_command import BuildDoc
+    # pylint: disable=unused-import
+    import recommonmark
     have_sphinx = True
 except ImportError:
     have_sphinx = False