Squashing your commits into one commit without using interactive rebase (https://github.com/edx/edx-platform/wiki/How-to-Rebase-a-Pull-Request#squash-your-changes)
This basically takes the diff of your branch + origin/master and sets them aside for you to "recommit" them.
git fetch -ap # get in sync w/ server
git checkout jscs-disallow-redundant-spaces # switch to the appropriate branch
git reset --hard origin/jscs-disallow-redundant-spaces # get my branch to be exactly the same as what's on the server
MERGE_BASE=$(git merge-base origin/jscs-disallow-redundant-spaces origin/master) # get the commit where your branch originates
git reset --mixed $MERGE_BASE # reset to the point where your branch originates, but put your changes like you just made them
git add . # stage your changes for a new commit
git commit -m 'Disallow spaces between brackets' # commit your new commit
git push origin jscs-disallow-redundant-spaces -f # force push it up to the server. you are rewriting history (check that everything looks ok before doing this)