failing Valhalla tests on Mac OS

[drewda]

When the Valhalla formula runs make test, it produces the following output:

==> make test
Last 15 lines from /Users/drew/Library/Logs/Homebrew/valhalla/05.make:
# TOTAL: 87
# PASS:  83
# SKIP:  0
# XFAIL: 0
# FAIL:  4
# XPASS: 0
# ERROR: 0
============================================================================
See ./test-suite.log
Please report to https://github.com/valhalla/valahlla/issues
============================================================================
make[3]: *** [test-suite.log] Error 1
make[2]: *** [check-TESTS] Error 2
make[1]: *** [check-am] Error 2
make: *** [check] Error 2

This is a known issue: valhalla/valhalla#977 and valhalla/valhalla#436