Update .gitignore for IntelliJ files.
Add migration for repository_name
Set repository_name on creation.

Validates uniqueness of repository_name
Add repository name to edit repository page.

Have project_params complain better if it can't parse a URL.
Use %r to avoid \/ in regexes.
Various specs need to be a bit more careful about repository names now.
Merge remote-tracking branch 'origin/jkingdon+mattwilson/repository-name'

* origin/jkingdon+mattwilson/repository-name:
  Add repository name to edit repository page.
  Set repository_name on creation.
  Add migration for repository_name
  Update .gitignore for IntelliJ files.