I keep forgetting how to resolve conflicts in git. This stackoverflow question seems to explain things quite nicely.
If there is a conflict git puts some lines in the conflicting file highlighting the conflict. You can open that file manually resolve the conflict. Manually resolving the conflict means editing the file to leave it as you want it in the final version.
Once you have resolved the conflict it should be possible to commit this change which will allow git(hub) to carry on.