fix running tests with glob on Windows: runtests.py test/unit/*_test.cpp now works
fix running tests with glob on Windows: runtests.py test/unit/*_test.cpp now works

stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math