Things are starting to work now...
* Now we extract the version number from package.json to use in making the plugin library
* We start building the whole site (eek, going to be slow)
For "master" we need to rebuild the prerelease; for "tiddlywiki-com" we need to rebuild the main release using the latest release. I want to have as much of the travis specific build logic expressed in travis.yml as possible, hence having to figure out Travis's syntax rather than doing everything in a script that tests the $TRAVIS_BRANCH environment variable...