Update CI wasm checker

Author: uint

.circleci/config.yml

@@ -907,7 +907,7 @@ jobs:
       - run:
           name: Install check_contract
           # Uses --debug for compilation speed
-          command: cargo install --debug --version 0.15.0 --features iterator --example check_contract -- cosmwasm-vm
+          command: cargo install --debug --version 0.16.0-rc2 --features iterator --example check_contract -- cosmwasm-vm
       - save_cache:
           paths:
             - /usr/local/cargo/registry