Fix Autobuild binder (#10)

* Add github workflow to autobuild binder

* fix autobuild binder

Author: dwhswenson

.github/workflows/binder.yml

@@ -11,4 +11,4 @@ jobs:
     steps:
       - uses: s-weigand/trigger-mybinder-build@v1
         with:
-          target-repo: openpathsampling/ops_tutorial
+          target-repo: openpathsampling/ops_tutorial/main