Switch to w3c/spec-prod to automate publication to /TR (#411)

The code currently relies on Travis CI. This update replaces that with the
w3c/spec-prod action and enables automatic publication.

Author: xfq

.github/workflows/auto-publish.yml

@@ -0,0 +1,25 @@
+# Workflow based on the w3c/spec-prod action example to deploy to W3C using Echidna:
+# https://github.com/w3c/spec-prod/blob/main/docs/examples.md#deploy-to-w3c-using-echidna
+
+name: CI
+
+on:
+  pull_request: {}
+  push:
+    branches: [main]
+
+jobs:
+  main:
+    name: Build, Validate and Deploy
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - uses: w3c/spec-prod@v2
+        with:
+          GH_PAGES_BRANCH: gh-pages
+          W3C_ECHIDNA_TOKEN: ${{ secrets.ECHIDNA_TOKEN }}
+          # Replace following with appropriate value. See options.md for details.
+          W3C_WG_DECISION_URL: https://lists.w3.org/Archives/Public/public-device-apis/2021May/0008.html
+          W3C_BUILD_OVERRIDE: |
+            status: CRD
+            shortname: generic-sensor

.travis.yml

@@ -18,12 +18,14 @@ Abstract:
   It does so by defining a blueprint for writing
   specifications of concrete sensors along with an abstract Sensor interface
   that can be extended to accommodate different sensor types.
-!Feedback: <a href="https://github.com/w3c/sensors">GitHub</a> (<a href="https://github.com/w3c/sensors/issues/new">new issue</a>, <a href="https://github.com/w3c/sensors/milestone/2">level 1 issues</a>, <a href="https://github.com/w3c/sensors/issues">all issues</a>)
+Issue Tracking: Generic Sensor API Issues Repository https://github.com/w3c/sensors/issues
 !Other: <a href="https://github.com/web-platform-tests/wpt/tree/master/generic-sensor">Test suite</a>, <a href="https://github.com/w3c/sensors/commits/main/index.bs">latest version history</a>, <a href="https://github.com/w3c/sensors/commits/gh-pages/index.bs">previous version history</a>
 Indent: 2
 Repository: w3c/sensors
 Markup Shorthands: markdown on
-Boilerplate: omit issues-index, omit conformance, omit feedback-header
+Boilerplate: omit issues-index, omit conformance, omit feedback-header, repository-issue-tracking no
+Include MDN Panels: if possible
+Implementation Report: https://www.w3.org/wiki/DAS/Implementations
 Ignored Vars: activated_sensors
 Inline GitHub Issues: yes
 Default Biblio Status: current