update integration test template

Author: ds300

integration-tests/newIntegrationTest.ts

@@ -35,12 +35,18 @@ spawnSafeSync("yarn", [], { cwd: testDir })
 // create shell script boilerplate
 fs.writeFileSync(
   path.join(testDir, `${testName}.sh`),
-  `# make sure errors stop the script
+  `#!/bin/bash
+# make sure errors stop the script
 set -e
 
+npm install
+
 echo "add patch-package"
-yarn add $1
-alias patch-package=./node_modules/.bin/patch-package
+npm add $1
+
+function patch-package {
+  ./node_modules/.bin/patch-package "$@"
+}
 `,
   { mode: 0o755 },
 )