Pull changes when working with an existing repository (#1341)
Pull changes when working with an existing repository (#1341)

* In the situation where the repository already exists, pull changes
  before attempting to reset ourselves to origin/branch to ensure that
  all of the origin changes are present.  Otherwise there may be
  additional changes on the origin that will cause push to fail.
karianna/openjdk-build,karianna/openjdk-build,AdoptOpenJDK/openjdk-build,AdoptOpenJDK/openjdk-build