Fix initial commit test
Fix initial commit test

`test_commit_commit__create_initial_commit_parent_not_current` was not correctly 
testing that `HEAD` was not changed. Now we grab the oid that it was pointing to
before the call to `git_commit_create` and the oid that it's pointing to afterwards
and compare those.
stewid/libgit2,stewid/libgit2,stewid/libgit2,stewid/libgit2,stewid/libgit2,Corillian/libgit2,Corillian/libgit2,Corillian/libgit2,Corillian/libgit2,Corillian/libgit2,stewid/libgit2,Corillian/libgit2