Add kcas

Author: patricoferris

.github/workflows/main.yml

@@ -54,12 +54,12 @@ jobs:
       - run: | 
           opam pin -yn eio.dev .
           opam pin -yn eio_windows.dev .
-          opam install ocamlfind.1.9.5 alcotest mdx crowbar -y
+          opam install ocamlfind.1.9.5 kcas alcotest mdx crowbar -y
           opam install eio eio_windows --deps-only
       - run: opam exec -- dune runtest
   docker:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
     - name: Build the Docker image
-      run: docker build .
+      run: docker build .