fix: handle UNKNOWN status and lint fix (#892)

Author: RafaelGSS

lib/prepare_release.js

@@ -40,7 +40,7 @@ export default class ReleasePreparation extends Session {
     const { cli } = this;
 
     cli.warn(`PR#${pr.number} - ${pr.title} is not 'MERGEABLE'.
-      So, it will be skipped. Status: ${pr.mergeable}`);
+      Status: ${pr.mergeable}`);
   }
 
   async getOpenPRs(filterLabels) {
@@ -66,7 +66,6 @@ export default class ReleasePreparation extends Session {
     for (const pr of prs) {
       if (pr.mergeable !== 'MERGEABLE') {
         this.warnForNonMergeablePR(pr);
-        continue;
       }
       const cp = new CherryPick(pr.number, this.dir, cli, {
         owner: this.owner,
@@ -486,7 +485,7 @@ export default class ReleasePreparation extends Session {
     let releaseHeader = `## ${date}, Version ${newVersion}` +
                           ` ${releaseInfo}, @${username}\n`;
     if (isSecurityRelease) {
-      releaseHeader += '\nThis is a security release.';
+      releaseHeader += '\nThis is a security release.\n';
     }
 
     const topHeader =