General adjustments

I updated the meme show page to only show edit/delete options for the author of the meme. Also updated the ER picture to be more accurate. Added in the older devise tests I had deleted off master. This way we should be able to keep the old tests we wrote and not have merge conflicts when merging in the carrierwave branch.
these are actually old tests from another branch (that still had them)... i deleted them but then we decided we should keep them haha. so I'm putting them back in here, so we can merge in the carrierwave branch which has the exact same ones. then we can edit them as needed. does that make sense?