git: Don't swallow all push output

[jerry-skydio]

In certain situations "git push" will need to auth interactively. However
we don't show the user any output from git push because of github's automatic
"create a pr test" that is generally not what we want since revup handles pr
creation. This does make these auth situations confusing though.

Instead of hiding all output, default to showing output except for lines prefixed
with "remote:" which will get hidden.

Topic: outpush2
Closes: #33

[jerry-skydio]

Reviews in this chain:
└#203 git: Don't swallow all push output

[jerry-skydio]

#	head	base	diff	date	summary
0	b12adb1e	c7b92e83	diff	Dec 28 16:22 PM	2 files changed, 20 insertions(+), 6 deletions(-)