travis: disable llvm.org-hosted clang versions

They are currently offline, I plan to revert this commit as soon as
they are back.

.travis-install-compiler.sh

@@ -12,10 +12,10 @@ case "${TRAVIS_OS_NAME}" in
 	sudo apt-add-repository -y ppa:ubuntu-toolchain-r/test
 
 	sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys AF4F7421
-	for CLANG_VERSION in 3.4 3.5 3.6 3.7; do
-            sudo apt-add-repository -y \
-		 "deb http://llvm.org/apt/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME}-${CLANG_VERSION} main"
-	done
+	# for CLANG_VERSION in 3.4 3.5 3.6 3.7; do
+        #     sudo apt-add-repository -y \
+	# 	 "deb http://llvm.org/apt/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME}-${CLANG_VERSION} main"
+	# done
 
 	sudo apt-get update -qq
 

.travis.yml

@@ -13,15 +13,15 @@ env:
     - COMPILER=gcc-5 CFLAGS="-fsanitize=address -fsanitize=undefined"
     - COMPILER=gcc-5 CFLAGS="-std=c11"
     - COMPILER=clang
-    - COMPILER=clang-3.7
+    # - COMPILER=clang-3.7
     - COMPILER=gcc-4.9 CFLAGS="-fsanitize=address -fsanitize=undefined"
     - COMPILER=clang-3.6 CFLAGS="-fsanitize=address -fsanitize=undefined"
     - COMPILER=gcc-4.8 CFLAGS="-fsanitize=address"
     - COMPILER=gcc-4.7
     - COMPILER=gcc-4.6
     - COMPILER=gcc-4.4
-    - COMPILER=clang-3.5 CFLAGS="-fsanitize=address -fsanitize=undefined"
-    - COMPILER=clang-3.4 CFLAGS="-fsanitize=address -fsanitize=undefined"
+    # - COMPILER=clang-3.5 CFLAGS="-fsanitize=address -fsanitize=undefined"
+    # - COMPILER=clang-3.4 CFLAGS="-fsanitize=address -fsanitize=undefined"
     - COMPILER=x86_64-w64-mingw32-gcc EXTENSION=".exe"
     - COMPILER=i686-w64-mingw32-gcc EXTENSION=".exe"
   global: