making python script runnable for pandoc
added shebang to the python pandoc script
Merge pull request #36 from twitwi/make-python-script-runnable-for-pandoc

making python script runnable for pandoc
Refactor out template validation logic in prep for cmd line rework
Proof of concept refactor to command line sig for @rgaia-cs (issue #34)
New rgaia-cs call signature
With no path provided, default to curdir, not a hard-coded default