requirements: Change the URL to use git+git.

Some versions of Pip, depending on the platform and Python version have
issues with git+https URL's.
Add nodes with missing timestamp to unreported nodes

Skip nodes with NoneType timestamps

add nodes with missing timestamp to unreported nodes
Merge pull request #25 from lsjostro/fix-nodes-without-timestamp

Add nodes with missing timestamp to unreported nodes
puppetboard/app.py: pep8