Update Git branches and the default (8.x-1.x) one.

Git errors:

(1.)
It appears you are working in the "feature1" branch in git. You should really be working in a version specific branch. The most direct documentation on this is Moving from a master branch to a version branch. For additional resources please see the documentation about release naming conventions and creating a branch in git.

(2.)
The following git branches do not match the release branch pattern, you should remove/rename them. See https://www.drupal.org/node/1015226

  8.x-1.0
  remotes/origin/8.x-1.0
  remotes/origin/HEAD -> origin/8.x-1.0

I hope this will help.
Thank you.