Fix linux-bazel build (#566)

Install bazel via apt-source
diff --git a/.travis.yml b/.travis.yml
index fe05e44..73a7615 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -235,10 +235,12 @@
       addons:
         apt:
           sources:
+            - sourceline: "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8"
+              key_url: "https://storage.googleapis.com/bazel-apt/doc/apt-key.pub.gpg"
             - ubuntu-toolchain-r-test
           packages:
-            - wget
-            - pkg-config
+            - oracle-java8-installer
+            - bazel
 
     - os: osx
       env: BUILD_SYSTEM=bazel
diff --git a/scripts/.travis.sh b/scripts/.travis.sh
index 5ca14f2..be9313e 100755
--- a/scripts/.travis.sh
+++ b/scripts/.travis.sh
@@ -2,17 +2,6 @@
 
 case "$1" in
     "before_install")
-	case "${TRAVIS_OS_NAME}" in
-	    "linux")
-		case "${BUILD_SYSTEM}" in
-		    "bazel")
-			wget https://github.com/bazelbuild/bazel/releases/download/0.4.5/bazel_0.4.5-linux-x86_64.deb
-			echo 'b494d0a413e4703b6cd5312403bea4d92246d6425b3be68c9bfbeb8cc4db8a55  bazel_0.4.5-linux-x86_64.deb' | sha256sum -c --strict || exit 1
-			sudo dpkg -i bazel_0.4.5-linux-x86_64.deb
-			;;
-		esac
-		;;
-	esac
 	;;
     "install")
 	case "${TRAVIS_OS_NAME}" in