tweak travis CI script for strange OS X build failure
tweak travis CI script for strange OS X build failure

dplarson/Mocha.jl,JuliaPackageMirrors/Mocha.jl,nstiurca/Mocha.jl,jeff-regier/Mocha.jl,jeff-regier/Mocha.jl,JuliaPackageMirrors/Mocha.jl,nstiurca/Mocha.jl,dplarson/Mocha.jl