change key

.travis.yml

@@ -78,7 +78,7 @@ before_install:
   - if [ "$TRAVIS_OS_NAME" = "linux" ]; then
       eval "${MATRIX_EVAL}";
       if [ -n "$MATRIX_EVAL" ] && [ "$TRAVIS_COMPILER" != "clang" ]; then
-        sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6B05F25D762E3157;
+        sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 1E9377A2BA9EF27F;
         sudo add-apt-repository -y ppa:ubuntu-toolchain-r/ppa;
         sudo apt-get update -qq;
         sudo apt-get install -y $CC;