remove then install

Author: tesuji

ci/integration-tests.sh

@@ -5,7 +5,8 @@ if [[ -z "$INTEGRATION" ]]; then
     exit 0
 fi
 
-cargo install -Z install-upgrade --debug --path .
+rm ~/.cargo/bin/cargo-clippy
+cargo install --force --debug --path .
 
 echo "Running integration test for crate ${INTEGRATION}"