Defer "Merging..." response until we actually know we're merging

[ChrisPenner]

Overview

Just a small nit, but pull would previously always print Merging... even on no-op pulls and fast-forwards which is confusing as an end user.

Now it waits until after the No-op and FF checks to say it's going to start a merge.

This does result in it showing "Merging..." in every call to merge though; so maybe we should just remove the message altogether? I'm not sure it's relevant.

Before:

simple/main> pull

  Merging...


  😶

  simple/main was already up-to-date with remote @chrispenner/simple/main.

After:

simple/main> pull

  😶

  simple/main was already up-to-date with remote @chrispenner/simple/main.

Implementation notes

Just move the Merging... response later in the process.

Test coverage

I tried it out

[mitchellwrosen]

Oops sorry I didn't notice this review request. I'd be more inclined to just remove the message as you mention; that way, neither pull nor merge have weird output. I can make that change on this branch since I took so long to review 👍