test_hyperexponential_distribution fails in debug builds on travis CI osx any xcode level (clang 4.2.1 for example)

[James E. King, III]

Appears to be platform related as debug builds on linux with clang (any version) do not fail this way.

​https://travis-ci.org/jeking3/random/builds/284931646

testing.capture-output bin.v2/libs/random/test/test_hyperexponential_distribution.test/clang-darwin-darwin-4.2.1/debug/threadapi-pthread/test_hyperexponential_distribution.run
====== BEGIN OUTPUT ======
Running 7 test cases...
libs/random/test/test_hyperexponential_distribution.cpp:275: error: in "test_streaming": check param == check_param has failed [[0.25 0.25 0.25 0.25] [1 2 3 4] != [1] [1]]
libs/random/test/test_hyperexponential_distribution.cpp:294: error: in "test_streaming": check param == check_param has failed [[0.1 0.2 0.3 0.4] [1 1 1 1] != [1] [1]]
*** 2 failures are detected in the test module "Master Test Suite"
EXIT STATUS: 201
====== END OUTPUT ======
bin.v2/libs/random/test/test_hyperexponential_distribution.test/clang-darwin-darwin-4.2.1/debug/threadapi-pthread/test_hyperexponential_distribution.run...