Finish first pass on editing links

- Can edit short, target, and expiration date
- Get around the short  PK by just making a copy and applying changes and then
saving it
4 jobs for 25-edit-links in 1 minute and 2 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #2262
Go-py2.7

00:00:53

passed #2263
Go-py3.4

00:01:01

passed #2264
Go-py3.5

00:00:57

passed #2265
Go-py3.6

00:01:01

73.0%