make LP user creation idempotent
LP has 50 character long usernames and since we don't know who is using them to login we are just going to allow longer usernames in discourse as well.
Remove ability to edit preferences from the UI for things that are managed by the LP profile.

  * Added a button to edit the preferences in LP profile.
Seed discourse with our community categories
[#65684824] LP Posts API now requires a category and comment is optional
Add ability to set created_at for the topic
Use find_or_initialize_by
do not structure dump on staging or production
Merge pull request #15 from LessonPlanet/jr/create-articles

Update API to accommodate creating topics from articles
Fix the clash of variable names
Merge branch 'development' into ps/style-discourse
Load up the style, header, and logo via the seed file.