Merge branch 'ls/travis-build-doc'

CI test was taught to build documentation pages.

* ls/travis-build-doc:
  travis-ci: build documentation

diff --combined .travis.yml
index 1fdcec8437a8c78b3697b0e0ca55eb2a0778541e,55299bd2bd0c87de19ba3dc41c4ef84923730515..adab5b89bba7b41a07a2a000dddbd4496ba7c7d3
--- 1/.travis.yml
--- 2/.travis.yml
+++ b/.travis.yml
@@@ -22,11 -22,8 +22,11 @@@ addons
  env:
    global:
      - DEVELOPER=1
 -    - P4_VERSION="15.2"
 -    - GIT_LFS_VERSION="1.1.0"
 +    # The Linux build installs the defined dependency versions below.
 +    # The OS X build installs the latest available versions. Keep that
 +    # in mind when you encounter a broken OS X build!
 +    - LINUX_P4_VERSION="16.1"
 +    - LINUX_GIT_LFS_VERSION="1.2.0"
      - DEFAULT_TEST_TARGET=prove
      - GIT_PROVE_OPTS="--timer --jobs 3 --state=failed,slow,save"
      - GIT_TEST_OPTS="--verbose --tee"
@@@ -35,23 -32,38 +35,38 @@@
      # t9816 occasionally fails with "TAP out of sequence errors" on Travis CI OS X
      - GIT_SKIP_TESTS="t9810 t9816"
  
+ matrix:
+   include:
+     - env: Documentation
+       os: linux
+       compiler: clang
+       addons:
+         apt:
+           packages:
+           - asciidoc
+           - xmlto
+       before_install:
+       before_script:
+       script: ci/test-documentation.sh
+       after_failure:
+ 
  before_install:
    - >
      case "${TRAVIS_OS_NAME:-linux}" in
      linux)
        mkdir --parents custom/p4
        pushd custom/p4
 -        wget --quiet http://filehost.perforce.com/perforce/r$P4_VERSION/bin.linux26x86_64/p4d
 -        wget --quiet http://filehost.perforce.com/perforce/r$P4_VERSION/bin.linux26x86_64/p4
 +        wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4d
 +        wget --quiet http://filehost.perforce.com/perforce/r$LINUX_P4_VERSION/bin.linux26x86_64/p4
          chmod u+x p4d
          chmod u+x p4
          export PATH="$(pwd):$PATH"
        popd
        mkdir --parents custom/git-lfs
        pushd custom/git-lfs
 -        wget --quiet https://github.com/github/git-lfs/releases/download/v$GIT_LFS_VERSION/git-lfs-linux-amd64-$GIT_LFS_VERSION.tar.gz
 -        tar --extract --gunzip --file "git-lfs-linux-amd64-$GIT_LFS_VERSION.tar.gz"
 -        cp git-lfs-$GIT_LFS_VERSION/git-lfs .
 +        wget --quiet https://github.com/github/git-lfs/releases/download/v$LINUX_GIT_LFS_VERSION/git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz
 +        tar --extract --gunzip --file "git-lfs-linux-amd64-$LINUX_GIT_LFS_VERSION.tar.gz"
 +        cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
          export PATH="$(pwd):$PATH"
        popd
        ;;