Install ccache on OSX Travis (#30111)

(cherry picked from commit 36d0116)

Author: staticfloat

.travis.yml

@@ -75,7 +75,7 @@ before_install:
         contrib/travis_fastfail.sh || exit 1;
         brew tap staticfloat/julia > /dev/null;
         brew rm --force $(brew deps --HEAD julia);
-        brew install -v gcc gmp mpfr pcre2 staticfloat/julia/openblas-julia staticfloat/julia/suite-sparse-julia staticfloat/juliadeps/libgfortran;
+        brew install -v ccache gcc gmp mpfr pcre2 staticfloat/julia/openblas-julia staticfloat/julia/suite-sparse-julia staticfloat/juliadeps/libgfortran;
         BUILDOPTS="-j3 USECLANG=1 USECCACHE=1 BINARYBUILDER_TRIPLET=x86_64-apple-darwin14 BINARYBUILDER_LLVM_ASSERTS=1";
         BUILDOPTS="$BUILDOPTS USE_BINARYBUILDER_LLVM=1 LLVM_CONFIG=$TRAVIS_BUILD_DIR/usr/tools/llvm-config LLVM_SIZE=$TRAVIS_BUILD_DIR/usr/tools/llvm-size";
         BUILDOPTS="$BUILDOPTS VERBOSE=1 USE_BLAS64=0 SUITESPARSE_INC=-I$(brew --prefix suite-sparse-julia)/include FORCE_ASSERTIONS=1";