Add support for Travis CI

- Verify that the the pdf can be generated without errors
- Publish the latest version to Github pages

The link to the pdf has also been added to the README.

.travis.yml

@@ -0,0 +1,17 @@
+sudo: required
+dist: trusty
+before_install:
+- sudo apt-get -qq update
+- sudo apt-get install -q -y texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended texlive-fonts-extra
+script:
+- make
+- mkdir build
+- cp openssl-book.pdf build
+deploy:
+  provider: pages
+  skip-cleanup: true
+  github-token: $GITHUB_TOKEN  # Set in travis-ci.org dashboard, marked secure
+  keep-history: true
+  local-dir: build
+  on:
+    branch: master

README

@@ -23,6 +23,9 @@ contain content that should enable the reader to get to a level of familiarity
 with OpenSSL that they can then use the other documentation sources (such as the
 man pages) to find detailed information as required.
 
+The latest version of the book is available at:
+https://openssl.github.io/openssl-book/openssl-book.pdf
+
 NOTE: This is a very initial draft and there is no content in the guide yet!
 
 Building the OpenSSL Guide