Release: v1.2.6 (#320)

## What's Changed
* chore: update dependencies (automated) by @verbanicm in
#312
* Relax app.yml detection to just "runtime" by @sethvargo in
#313
* Switch to pull non-secret values from env by @sethvargo in
#314
* Release: v1.2.3 by @google-github-actions-bot in
#316
* Release: v1.2.4 by @google-github-actions-bot in
#317
* Release: v1.2.5 by @google-github-actions-bot in
#319


**Full Changelog**:
v1.2.2...1531cb0

Author: google-github-actions-bot

dist/index.js

@@ -1,6 +1,6 @@
 {
   "name": "deploy-appengine",
-  "version": "1.2.5",
+  "version": "1.2.6",
   "description": "Github Action: Deploy to Google App Engine",
   "main": "dist/index.js",
   "scripts": {