Update .travis.yml

Author: chrisdembia

.travis.yml

@@ -149,8 +149,8 @@ before_install:
   ## Doxygen.
   # Need a doxygen that is more recent than that available through apt-get.
   - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then mkdir ~/doxygen && cd ~/doxygen; fi
-  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then wget https://sourceforge.net/projects/doxygen/files/rel-1.8.14/doxygen-1.8.14.linux.bin.tar.gz; fi
-  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then tar xzf doxygen-1.8.14.linux.bin.tar.gz; fi
+  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then wget https://sourceforge.net/projects/doxygen/files/rel-1.8.10/doxygen-1.8.10.linux.bin.tar.gz; fi
+  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then tar xzf doxygen-1.8.10.linux.bin.tar.gz; fi
   - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "osx" ]]; then brew install doxygen; fi
 
   ## Install Simbody.
@@ -225,7 +225,7 @@ install:
 
   # Doxygen.
   - OSIM_CMAKE_ARGS+=(-DOPENSIM_DOXYGEN_USE_MATHJAX=off -DOPENSIM_SIMBODY_DOXYGEN_LOCATION="https://simtk.org/api_docs/simbody/latest/")
-  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then OSIM_CMAKE_ARGS+=(-DDOXYGEN_EXECUTABLE=$HOME/doxygen/doxygen-1.8.14/bin/doxygen); fi
+  - if [[ "$DOXY" = "on" && "$TRAVIS_OS_NAME" = "linux" ]]; then OSIM_CMAKE_ARGS+=(-DDOXYGEN_EXECUTABLE=$HOME/doxygen/doxygen-1.8.10/bin/doxygen); fi
 
   - printf '%s\n' "${OSIM_CMAKE_ARGS[@]}"
   - cmake "${OSIM_CMAKE_ARGS[@]}"