deploy to GH pages

http://www.steveklabnik.com/automatically_update_github_pages_with_travis_example/

.travis.yml

@@ -1,13 +1,16 @@
 sudo: false
 language: rust
-
 rust:
   - nightly
   - beta
   - stable
   - 1.5.0
-
 before_script:
   - cargo install mdbook
 script:
   - PATH=$PATH:/home/travis/.cargo/bin make all
+after_success:
+  - test $TRAVIS_PULL_REQUEST == "false" && test $TRAVIS_BRANCH == "master" && bash deploy.sh
+env:
+  global:
+    secure: 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

deploy.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -o errexit -o nounset
+
+rev=$(git rev-parse --short HEAD)
+
+cd book
+
+git init
+git config user.name "Steve Klabnik"
+git config user.email "steve@steveklabnik.com"
+
+git remote add upstream "https://$GH_TOKEN@github.com/rust-lang/rust-by-example.git"
+git fetch upstream
+git reset upstream/gh-pages
+
+touch .
+
+git add -A .
+git commit -m "rebuild pages at ${rev}"
+git push -q upstream HEAD:gh-pages