trying to install 32-bit libs

.travis.yml

@@ -17,7 +17,7 @@ addons:
     build_command: make
     branch_pattern: coverity_scan
 before_install:
-   - sudo aptitude install ia32-libs
+   - sudo apt-get install ia32-libs
    - sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
    - sudo add-apt-repository ppa:kalakris/cmake -y
    - sudo apt-get update -qq