build(rollup): downgraded the babel plugin

until the project gets updated to use babel v7

Author: travi

package-lock.json

@@ -31,7 +31,7 @@
     "test:integration:debug": "DEBUG=test run-s test:integration",
     "test:integration:wip": "run-s 'test:integration:base -- --tags @wip'",
     "test:integration:focus": "run-s 'test:integration:base -- --tags @focus'",
-    "test": "npm-run-all --print-label --parallel lint:* --parallel test:*",
+    "test": "npm-run-all --print-label --parallel lint:* --parallel test:* --serial build",
     "commitmsg": "commitlint -e",
     "precommit": "npm test",
     "build": "rollup -c",
@@ -75,7 +75,7 @@
     "nyc": "^14.1.1",
     "proxyquire": "^2.1.3",
     "rollup": "^1.20.3",
-    "rollup-plugin-babel": "^4.3.3",
+    "rollup-plugin-babel": "^3.0.7",
     "rollup-plugin-node-resolve": "^5.2.0",
     "sinon": "^7.4.2"
   },

package.json

@@ -6,7 +6,6 @@ export default {
   input: 'src/plugin.js',
   external: [
     'http-status-codes',
-    'highwire',
     'delay',
     'joi',
     'hoek',