Remove underscores from categories and test

I re-deployed the appstore to devappstore5 for testing after "blowing away" the old data, since the new underscore-free categories were simply getting added to the existing ones.
I assigned a bunch of new categories to the apps and noticed they are being displayed correctly and also the left-side search tool radio buttons are working as expected. Moving to closed.

Please note: The devappstore5 has the latest master branch code, but I did not "blow away" the database and S3 bucket when I re-deployed the code. Just letting you know about that because the site is not a completely "fresh" site.

The underscores are now removed and the UI looks OK.

But we do want to make sure we test this well because there could be unforeseen side effects.

To test, make sure that you can select and add one a category that contains a space. You can do this by logging in as "admin". (DM me if you need the password.) Then, if you visit an app's page, you should see an "edit" button there. If yes, then you can use the interface to assign the app to any category you want. Please try assigning it to a category that contains a space in the name to ensure this will properly work.

Also, do please log in to the host & check error files for potential problems.

Do please make this a high priority for testing when you get the chance!

cc: Chirag Chandrahas Shetty, Sai Supreeth Segu, and Sameer Shanbhag

Merged and deployed to https://devappstore5.bioviz.org

Dr. [~aloraine] and Sameer Shanbhag, I have resolved the conflict and updated the pull request. If everyone is Ok with the change then we can merge the PR.
Link for pull request: https://bitbucket.org/lorainelab/appstore/pull-requests/241