update to trusty distro, remove 3rd-party PPAs for testing

scripts/travis

@@ -21,9 +21,6 @@ if [ "x$ARCH" = "xnative" ]; then
 		make
 		make test
 	else
-		sudo apt-get update
-		sudo apt-get install -y python-software-properties
-		sudo apt-add-repository -y ppa:kalakris/cmake
 		sudo apt-get update
 		sudo apt-get install -y cmake ninja-build
 		cmake -GNinja ..
@@ -38,10 +35,6 @@ else
 	export CC=$CPU-w64-mingw32-gcc
 
 	if [ -z $(which $CC) ]; then
-		# Update Ubuntu 12.04 with current mingw toolchain
-		sudo apt-get update
-		sudo apt-get install -y python-software-properties
-		sudo apt-add-repository -y ppa:tobydox/mingw-x-precise
 		sudo apt-get update
 		sudo apt-get install -y $ARCH-x-gcc make
 		export PATH=$PATH:/opt/$ARCH/bin