Travis: Fix Linux build and disallow failures

.travis-install-deps.sh

@@ -7,5 +7,5 @@ if [[ $TRAVIS_OS_NAME == 'osx' ]]; then
 	brew install scons sfml
 else
 	sudo apt-get update -qq
-	sudo apt-get install -qq libsfml-dev libboost-dev
+	sudo apt-get install -qq libsfml-dev libboost-dev libboost-filesystem-dev libboost-thread-dev
 fi

.travis.yml

@@ -9,8 +9,6 @@ compiler:
  - clang
 
 matrix:
- allow_failures:
-  - os: linux
  include:
   - os: linux
     sudo: required

SConstruct

@@ -235,7 +235,7 @@ if not env.GetOption('clean'):
 			print disp, 'must be installed!'
 			Exit(1)
 
-	boost_versions = ['-1_55', '-1_56', '-1_57', '-1_58'] # This is a bit of a hack. :(
+	boost_versions = ['-1_54', '-1_55', '-1_56', '-1_57', '-1_58'] # This is a bit of a hack. :(
 	bundled_libs = []
 
 	check_header('boost/lexical_cast.hpp', 'Boost.LexicalCast')