Add bump github action

.github/workflows/bump.yml

@@ -0,0 +1,15 @@
+name: 'Automatic version updates'
+on:
+  schedule:
+    # minute hour dom month dow (UTC)
+    - cron: '0 10 * * *'
+jobs:
+  version_update:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - uses: wader/bump@master
+        with:
+          bump_files: Dockerfile
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Dockerfile

@@ -1,7 +1,9 @@
-ARG GO_VERSION=1.13
+# bump: golang /GOLANG_VERSION=([\d.]+)/ docker:golang|^1
-ARG YDL_VERSION=2019.09.12.1
+ARG GOLANG_VERSION=1.13.3
+# bump: youtube-dl /YDL_VERSION=([\d.]+)/ https://github.com/ytdl-org/youtube-dl.git|/^\d/|sort
+ARG YDL_VERSION=2019.10.29
 
-FROM golang:$GO_VERSION
+FROM golang:$GOLANG_VERSION
 ARG YDL_VERSION
 
 RUN \