Build and install gtest as part of CI

.travis.yml

@@ -8,11 +8,15 @@ compiler:
 
 before_install:
   - sudo apt-get update -qq
-  - sudo apt-get install libboost-system-dev libboost-thread-dev
+  - sudo apt-get install build-essential cmake libboost-system-dev libboost-thread-dev libgtest-dev
+  - cd /usr/src/gtest
+  - sudo cmake CMakeLists.txt
+  - sudo make
+  - sudo cp *.a /usr/lib
 
 script:
+  - cd ${TRAVIS_BUILD_DIR}
   - cmake --version
   - cmake .
   - make
-  - export GTEST_OUTPUT="xml:test_results/" 
   - make test