Require explicit "write" perms to link BB repo
Require explicit "write" perms to link BB repo

- This is consistent with the GitHub addon, and internally consistent
    for BitBucket across personal and team repos.
- Perm level for personal repos changed from "owner" to "contributor"
- Perm level for team repos changed from "member" to "contributor"

felliott/osf.io,felliott/osf.io,baylee-d/osf.io,Johnetordoff/osf.io,felliott/osf.io,CenterForOpenScience/osf.io,Johnetordoff/osf.io,adlius/osf.io,felliott/osf.io,mfraezz/osf.io,CenterForOpenScience/osf.io,aaxelb/osf.io,mfraezz/osf.io,Johnetordoff/osf.io,Johnetordoff/osf.io,brianjgeiger/osf.io,cslzchen/osf.io,CenterForOpenScience/osf.io,aaxelb/osf.io,brianjgeiger/osf.io,cslzchen/osf.io,mfraezz/osf.io,baylee-d/osf.io,baylee-d/osf.io,aaxelb/osf.io,mfraezz/osf.io,adlius/osf.io,CenterForOpenScience/osf.io,brianjgeiger/osf.io,brianjgeiger/osf.io,cslzchen/osf.io,aaxelb/osf.io,cslzchen/osf.io,adlius/osf.io,adlius/osf.io