"Get branch (by name)" API is missing

[cvrebert]

jcabi-github currently seems to lack a way to access GitHub's "get repository branch (by name)" API:
https://developer.github.com/v3/repos/#get-branch

[dmarkov]

@yegor256 dispatch this issue please

[0crat]

Job #1086 is now in scope, role is DEV

[0crat]

Thanks for your contribution, @cvrebert/z! If you would be a member of the project, you would now earn +15 reputation points, as explained in §29. You can join and apply to it, see §2.

[0crat]

The job #1086 assigned to @paulodamaso/z, here is why; the budget is 30 minutes, see §4; please, read §8 and §9; if the task is not clear, read this and this; there will be no monetary reward for this job

[0pdd]

@cvrebert the puzzle #1457 is still not solved.

[0crat]

The job #1086 is now out of scope

[0crat]

Order was finished: +30 point(s) just awarded to @paulodamaso/z

[0pdd]

@cvrebert the only puzzle #1457 is solved here.