Install doxygen 1.8.14 on travis

Author: peterschrammel

.travis.yml

@@ -53,10 +53,23 @@ jobs:
             - sourceline: 'deb http://packages.cloud.google.com/apt cloud-sdk-trusty main'
               key_url: 'https://packages.cloud.google.com/apt/doc/apt-key.gpg'
           packages:
-            - doxygen
+            - cmake
             - google-cloud-sdk
       install:
-      script: scripts/travis_doxygen.sh
+      script:
+        - export DOXYGEN_VERSION=1.8.14
+        - wget http://ftp.stack.nl/pub/users/dimitri/doxygen-$(DOXYGEN_VERSION).src.tar.gz
+        - tar xfz doxygen-$(DOXYGEN_VERSION).src.tar.gz
+        - cd doxygen-$(DOXYGEN_VERSION)
+        - mkdir build
+        - cd build
+        - cmake ..
+        - make -j4
+        - cd ../..
+        - export PATH=$PATH:`pwd`/doxygen-$(DOXYGEN_VERSION)/build/bin
+        - echo $PATH
+        - doxygen --version
+        - scripts/travis_doxygen.sh
       before_cache:
       after_success:
         # Google Cloud Integration