experiment code to go with the dev branch (at the moment) of the cochrane-nlp code

NOTE

• This requires cochrane-nlp to be accessible as a module
• To do this
  • clone cochrane-nlp into a 'cochranenlp' directory (note no hyphen to conform with python module naming)
  • add the directory containing cochranenlp to the $PYTHONPATH environment variable, e.g. at the command line: export PYTHONPATH=$PYTHONPATH:/Users/bwallace/dev/cochrane/.