Removed CXXSTD 03 in ci configs for osx to get rid of dependent compi… #15

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Job	Run time
osx (TOOLSET=clang CXXSTD=11,14,1z Job 5, boost, macos-11, clang++, 11.7, clang, 11,14,1z)	15m 28s
posix (TOOLSET=gcc CXXSTD=11 Job 0, boost, ubuntu-20.04, ubuntu:16.04, g++, gcc, 11)	7m 22s
posix (TOOLSET=gcc-5 CXXSTD=11,14,1z Job 1, boost, g++-5, ubuntu-20.04, ubuntu:16.04, g++-5, gcc-...	10m 15s
posix (TOOLSET=gcc-6 CXXSTD=11,14,1z Job 2, boost, g++-6, ubuntu-20.04, ubuntu:16.04, g++-6, gcc-...	12m 22s
posix (TOOLSET=gcc-7 CXXSTD=11,14,17 Job 3, boost, g++-7, ubuntu-20.04, ubuntu:16.04, g++-7, gcc-...	11m 1s
posix (TOOLSET=clang CXXSTD=11,14,1z Job 4, boost, libstdc++-4.9-dev clang, ubuntu-20.04, ubuntu:...	11m 48s
	1h 8m 16s

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