*DO NOT MERGE* CME dump_userinfo management command

This includes two commits from Joe and I.  The first creates the dump_userinfo.py file which contains the first draft of the management command.  Following the creation of this file, Joe collected an initial output.csv which was forwarded to the CME accreditation team for feedback by Greg.  A few weeks down the line, Greg received feedback from them in the form of comments on data order and structure.  Last week, I took the opportunity to revise the command to bring it into compliance with the feedback and have collected a new output.csv and sent it back on to Greg for (hopefully) approval by CME.  There were also a few minor bug fixes included in my revisions. @jrbl @stvstnfrd @gbruhns 
Let's throw a XXX comment in here to the effect that we know having hardcoded credit count is janky but that's how it is for now, and that we'll need to revisit in the future when we have a way to get the credit counts out of a course.