Address WebAudio#114: Display spec

PR Preview app and Travis CI github apps already installed.  This just
copies over .travis.yml from the v1 spec to here.

Let's see if this is enough.

.travis.yml

@@ -0,0 +1,24 @@
+language: python
+sudo: false
+python:
+  - "3.7"
+
+install:
+  # Setup bikeshed. See https://tabatkins.github.io/bikeshed/#install-final
+  # - pip3 install bikeshed && bikeshed update
+  # Or do a clone.  The above method is preferred, but see issue #2262.
+  - git clone https://github.com/tabatkins/bikeshed.git
+  - (cd bikeshed; pip3 install -e .)
+  - bikeshed update
+  - bikeshed --version
+
+script:
+  - bash ./compile.sh
+
+deploy:
+  provider: pages
+  skip-cleanup: true
+  github-token: $GITHUB_DEPLOY_TOKEN
+  keep-history: true
+  on:
+    branch: main