ci: Force push to gh-pages

* Avoids issues when multiple commits get added to master and one's docs
  build is in progress before the other kicks off.

Signed-off-by: John Andersen <[email protected]>

Author: pdxjohnny

.ci/run.sh

@@ -185,7 +185,7 @@ function run_docs() {
   export GIT_SSH_COMMAND="${GIT_SSH_COMMAND} -o IdentityFile=~/.ssh/github_dffml"
 
   git remote set-url origin [email protected]:intel/dffml
-  git push
+  git push -f
 
   cd -