Travis CI: Try deleting and recreating .travis.yml

It appears to have worked for some people c.f. stackoverflow

.travis.yml

@@ -1,34 +0,0 @@
-language: node_js
-  - 12
-
-stages:
-  - name: test
-  - name: build-prerelease
-    if: branch = "master"
-  - name: build-tiddlywiki-com
-    if: branch = "tiddlywiki-com"
-
-jobs:  
-  include:
-    - stage: test
-      script: ./bin/test.sh
-    - stage: build-prerelease
-      script:
-        - ./bin/travis-pre-build.sh
-        - export TW5_BUILD_TIDDLYWIKI='./tiddlywiki.js'
-        - export TW5_BUILD_VERSION=$(./bin/get-plugin-library-version-number)
-        - export TW5_BUILD_DETAILS="Prerelease built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date +'%F %T %Z')"
-        - export TW5_BUILD_MAIN_EDITION='./editions/prerelease'
-        - export TW5_BUILD_OUTPUT='./output/prerelease'
-        - ./bin/build-site.sh || travis_terminate 1
-        - ./bin/travis-push.sh || travis_terminate 1
-    - stage: build-tiddlywiki-com
-      script:
-        - ./bin/travis-pre-build.sh
-        - export TW5_BUILD_TIDDLYWIKI='./node_modules/tiddlywiki/tiddlywiki.js'
-        - export TW5_BUILD_VERSION=$(./bin/get-plugin-library-version-number)
-        - export TW5_BUILD_DETAILS="Built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date +'%F %T %Z')"
-        - export TW5_BUILD_MAIN_EDITION='./editions/tw5.com'
-        - export TW5_BUILD_OUTPUT='./output'
-        - ./bin/build-site.sh || travis_terminate 1
-        - ./bin/travis-push.sh || travis_terminate 1