Add auto publish of website to Travis

.travis.yml

@@ -51,15 +51,15 @@ stages:
   - name: release
     if: ((branch = master AND type = push) OR (tag IS present)) AND NOT fork
 
+script: sbt ++$TRAVIS_SCALA_VERSION coverage test &&
+  sbt ++$TRAVIS_SCALA_VERSION core/coverageReport &&
+  sbt ++$TRAVIS_SCALA_VERSION coverageAggregate &&
+  sbt ++$TRAVIS_SCALA_VERSION coveralls
 
 jobs:
   include:
-    - env: TEST="bitcoin-s test suite"
-      script:
-        sbt ++$TRAVIS_SCALA_VERSION coverage test &&
-        sbt ++$TRAVIS_SCALA_VERSION core/coverageReport &&
-        sbt ++$TRAVIS_SCALA_VERSION coverageAggregate &&
-        sbt ++$TRAVIS_SCALA_VERSION coveralls
     # run ci-release only if previous stages passed
     - stage: release
       script: sbt ci-release
+    # run website push only if previous stages passed
+    - script: sbt docs/docusaurusPublishGhpages