Update Github actions

.github/labeler.yml

@@ -0,0 +1,15 @@
+# Add 'test' label
+":label: test :checkered_flag:":
+  - test/**/*
+
+# Add github actions related updates to .github
+":label: github-action :octocat:":
+  - .github/**/*
+
+# requirements.txt update
+":label: requirements-update :christmas_tree:":
+  - requirements/*
+
+":label: documentation :scroll:":
+  - README.md
+  - documentation/*.md

.github/workflows/greetings.yml

@@ -0,0 +1,13 @@
+name: Greetings
+
+on: [pull_request, issues]
+
+jobs:
+  greeting:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/first-interaction@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        issue-message: "You just reported your first issue in this repo. :thought_balloon: :sparkles: "
+        pr-message: "Congrats on your first contribution! :1st_place_medal: "

.github/workflows/label.yml

@@ -0,0 +1,19 @@
+# This workflow will triage pull requests and apply a label based on the
+# paths that are modified in the pull request.
+#
+# To use this workflow, you will need to set up a .github/labeler.yml
+# file with configuration.  For more information, see:
+# https://github.com/actions/labeler/blob/master/README.md
+
+name: Labeler
+on: [pull_request]
+
+jobs:
+  label:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/labeler@v2
+      with:
+        repo-token: "${{ secrets.GITHUB_TOKEN }}"

.github/workflows/stale.yml

@@ -0,0 +1,19 @@
+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+  - cron: "0 0 * * *"
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v1
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'Stale issue message'
+        stale-pr-message: 'Stale pull request message'
+        stale-issue-label: 'no-issue-activity'
+        stale-pr-label: 'no-pr-activity'