Tweak travis config to upload docs

.travis.yml

@@ -1 +1,20 @@
 language: rust
+sudo: false
+script:
+  - cargo build --verbose
+  - cargo test --verbose
+  - rustdoc --test README.md -L target/debug -L target/debug/deps
+  - cargo doc
+after_success: |
+  [ $TRAVIS_BRANCH = master ] &&
+  [ $TRAVIS_PULL_REQUEST = false ] &&
+  echo '<meta http-equiv=refresh content=0;url=unicode-width/index.html>' > target/doc/index.html &&
+  pip install ghp-import --user $USER &&
+  $HOME/.local/bin/ghp-import -n target/doc &&
+  git push -qf https://${TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git gh-pages
+env:
+  global:
+    secure: sF21oZa17vX3iE16x7lt2VsdcSYUJ5PtEwJzQ9Ab/0zFaNc5LUXFUOBddMS9LxYnwO1WI9iOVOYC2NbXT4oRgjZ2cmkatoE6nGHmkqUe4paxVy1Fg6ncjYO1jZwoRSSn1mi0CcwoHq46r2l6FaD0InJExwa3dzk63B9SjIUiekw=
+notifications:
+  email:
+    on_success: never