homebrew bottle caching appears to be broken

we're not running on osx travis at the moment so haven't noticed
homebrew has switched from sourceforge to bintray which should be more reliable anyway

[ci skip]

.travis.yml

@@ -39,8 +39,6 @@ before_install:
  brew tap staticfloat/julia;
  brew rm --force $(brew deps --HEAD julia);
  brew update;
- sed -i '' -e "s@https://downloads.sf.net/project/machomebrew/Bottles@https://cache.e.ip.saba.us/https://downloads.sf.net/project/machomebrew/Bottles@" /usr/local/Library/Homebrew/software_spec.rb;
- sed -i '' -e "s@https://homebrew.bintray.com@https://cache.e.ip.saba.us/https://homebrew.bintray.com@" /usr/local/Library/Homebrew/software_spec.rb;
  brew install -v --only-dependencies --HEAD julia;
  BUILDOPTS="USECLANG=1 LLVM_CONFIG=$(brew --prefix llvm33-julia)/bin/llvm-config-3.3 VERBOSE=1 USE_BLAS64=0 SUITESPARSE_INC=-I$(brew --prefix suite-sparse-julia)/include";
  BUILDOPTS="$BUILDOPTS LIBBLAS=-lopenblas LIBBLASNAME=libopenblas LIBLAPACK=-lopenblas LIBLAPACKNAME=libopenblas";