[tests] Use `awk` instead of `sed` to insert version number
[tests] Use `awk` instead of `sed` to insert version number

Summary:
The default `sed` installed on OS X chokes when encountering some combination of color control characters and non-ASCII unicode characters. This issue manifested as a failure in the `coverage` tests.

Fortunately, `awk` seems to not suffer from this problem.

Reviewed By: mroch

Differential Revision: D13401492

fbshipit-source-id: 54999def28f418447b965094ec2d5e261ac32bcb

popham/flow,samwgoldman/flow,gabelevi/flow,samwgoldman/flow,popham/flow,popham/flow,AgentME/flow,facebook/flow,facebook/flow,facebook/flow,gabelevi/flow,facebook/flow,samwgoldman/flow,samwgoldman/flow,AgentME/flow,mroch/flow,mroch/flow,AgentME/flow,samwgoldman/flow,gabelevi/flow,AgentME/flow,popham/flow,samwgoldman/flow,gabelevi/flow,AgentME/flow,mroch/flow,mroch/flow,gabelevi/flow,samwgoldman/flow,gabelevi/flow,popham/flow,popham/flow,gabelevi/flow,mroch/flow,facebook/flow,mroch/flow,popham/flow,facebook/flow,facebook/flow,mroch/flow