remove backport in travis setup. The link is dead now. Plus we no longer need the backport for a newer version of cmake
@@ -29,7 +29,6 @@ matrix:
apt:
sources:
- ubuntu-toolchain-r-test # For newer GCC
- - george-edison55-precise-backports # For cmake
- llvm_toolchain-trusty-7
packages:
- autoconf
