Create release note in CI (#6218)

.grenrc.js

+module.exports = {
+  template: {
+    commit: ({message, url, author, name}) => `- [${message}](${url}) - ${author ? `@${author}` : name}`,
+    issue: "- {{name}} [{{text}}]({{url}})",
+    label: "[**{{label}}**]",
+    noLabel: "closed",
+    group: "\n#### {{heading}}\n",
+    changelogTitle: "# Changelog\n\n",
+    release: "## {{release}} ({{date}})\n{{body}}",
+    releaseSeparator: "\n---\n\n"
+  },
+  groupBy: {
+    "Enhancements:": ["type: accepted/enhancement", "internal"],
+    "Bug Fixes:": ["type: accepted/bug"],
+    "Features": ["feature"]
+  },
+  ignoreIssuesWith: [
+    "skip-changelog"
+  ],
+  ignoreTagsWith: [
+    "snapshot",
+    "v1",
+    "v2"
+  ],
+  dataSource: "prs",
+  changelogFilename: "CHANGELOG.gren.md",
+  override: true,
+  generate: true
+}

package.json

     "tslint": "5.x.x",
     "typedoc": "0.x.x",
     "typescript": "3.2.2",
-    "identity-obj-proxy": "3.0.0"
+    "identity-obj-proxy": "3.0.0",
+    "github-release-notes": "0.17.3"
   },
   "jest": {
     "preset": "react-native",

scripts/release.js

     exec.execSync(`git add package.json`);
     exec.execSync(`git commit -m"Update package.json version to ${version} [ci skip]"`);
     exec.execSync(`git push deploy ${BRANCH}`);
+    draftGitRelease(version);
+}
+
+function draftGitRelease(version) {
+    exec.execSync(`npx gren release --tags=${version}`);
 }
 
 run();