bump version to 0.20.0 (#22)

Author: rahulku

action.yml

@@ -33,16 +33,16 @@ runs:
     - name: Install Rust
       uses: actions-rs/[email protected]
       with:
-        # From https://github.com/model-checking/kani/blob/kani-0.19.0/rust-toolchain.toml
+        # From https://github.com/model-checking/kani/blob/kani-0.20.0/rust-toolchain.toml
         # Should be updated every time we update the version to keep in sync.
         # This should be automated https://github.com/model-checking/kani-github-action/issues/9
-        toolchain: nightly-2022-11-20
+        toolchain: nightly-2022-12-11
         override: true
 
     - name: Install Kani
       shell: bash
       run: |
-        export KANI_VERSION="0.19.0";
+        export KANI_VERSION="0.20.0";
         cargo install --version $KANI_VERSION --locked kani-verifier;
         cargo-kani setup;