Add notes about updating the pipfile and requirements

Pipfile

@@ -1,8 +1,15 @@
+# Note that there is a devrequirements.txt file in this project, if you are 
+# updating this Pipfile make sure to update the devrequirements.txt accordingly
+
 [dev-packages]
-pyyaml="*"
 pytest="*"
 wheel="*"
 pytest-cov="*"
+PyYAML = "*"
+recommonmark = "*"
+alabaster = "*"
+Sphinx = ">=1.4,!=1.5.4"
+alabaster_jupyterhub = "*"
 
 [packages]
 repo2docker = {path=".", editable=true}

dev-requirements.txt

@@ -1,4 +1,5 @@
-pyyaml
+# Note that there is also a Pipfile for this project if you are updating this 
+# file do not forget to update thr Pipfile accordingly
 pytest
 wheel
 pytest-cov