Does it install these packages at all???.

.travis.yml

@@ -5,13 +5,13 @@ addons:
   apt:
     sources: 
       - ubuntu-toolchain-r-test
-      - llvm-toolchain-trusty-6.0
-      - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-6.0 main'
+      - llvm-toolchain-trusty-5.0
+      - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-5.0 main'
         key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
     packages:
       - g++-7
       - g++-8
-      - clang-6.0
+      - clang-5.0
   coverity_scan:
     project:
       name: "ChaiScript/ChaiScript"
@@ -42,11 +42,11 @@ matrix:
     - os: osx
       compiler: clang
       #osx_image: xcode10
-      env: CLANG_VER="6.0"
+      env: CLANG_VER="5.0"
     - os: osx
       compiler: clang
       #osx_image: xcode10
-      env: CLANG_VER="6.0" CMAKE_OPTIONS="-D DYNLOAD_ENABLED:BOOL=FALSE -D MULTITHREAD_SUPPORT_ENABLED:BOOL=FALSE -D USE_STD_MAKE_SHARED:BOOL=TRUE" BUILD_ONLY=1
+      env: CLANG_VER="5.0" CMAKE_OPTIONS="-D DYNLOAD_ENABLED:BOOL=FALSE -D MULTITHREAD_SUPPORT_ENABLED:BOOL=FALSE -D USE_STD_MAKE_SHARED:BOOL=TRUE" BUILD_ONLY=1
   
 env:
   global:
@@ -59,10 +59,6 @@ before_install:
   - if [ "${CLANG_VER}" != "" ]; then export CXX="clang++-$CLANG_VER" CC="clang-$CLANG_VER" ; fi
   - pip install --user cpp-coveralls
 
-install:
-  - sudo apt-get install --allow-unauthenticated -qq clang-6.0
-  - sudo apt-get install --allow-unauthenticated -qq clang++-6.0
-
 script: 
   - cmake -D ENABLE_COVERAGE:BOOL=TRUE -D CMAKE_BUILD_TYPE:STRING=Debug $CMAKE_OPTIONS . 
   - cmake --build . -- -j2