CXX-74 enable clang support for travis-ci

Signed-off-by: Andrew Morrow <acm@mongodb.com>

Author: TylerBrock

.travis.yml

@@ -2,25 +2,30 @@ language: cpp
 
 compiler:
     - gcc
+    - clang
 
 env:
   global:
     - PREFIX=$(mktemp -d /tmp/mongo-cxx-driver-install.XXXXXX || exit 1)
 
 # Setup required repositories before installation
 before_install:
-    - sudo add-apt-repository -y ppa:boost-latest/ppa
+    - sudo add-apt-repository -y ppa:jkeiren/ppa
     - sudo apt-get update -qq
 
-# Install the latest boost version
+# Install Boost 1.49 dependencies via PPA
 install:
-    - sudo apt-get install -qq libboost1.55-all-dev
+    - sudo apt-get install -qq
+      libboost1.49-dev
+      libboost-program-options1.49-dev
+      libboost-filesystem1.49-dev
+      libboost-thread1.49-dev
 
 script:
-    - $CXX --version
     - scons
        -j2
        --mute
+       --quiet
        --prefix=$PREFIX
        --use-system-boost
        --full