Test fails on Fedora rawhide

[opoplawski]

Test fails on Fedora rawhide with gcc 5.0.0 and C++11:

Checking test dependency graph end
test 1
    Start 1: test_kahan_sum
1: Test command: /builddir/build/BUILD/libmpdataxx-1.0.1/tests/unit/build/kahan_sum/test_kahan_sum
1: Test timeout computed to be: 9.99988e+06
1: (0,9)
1: [ 100000000 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 ]
1:       blitz::sum = 100000000.00000010431
1:        kahan_sum = 100000000.00000008941
1: (0,9)
1: [ 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 9.9999999392252902908e-09 100000000 ]
1: rev + blitz::sum = 100000000.00000008941
1: rev +  kahan_sum = 100000000.00000008941
1: terminate called after throwing an instance of 'std::runtime_error'
1:   what():  A
1/5 Test #1: test_kahan_sum ...................***Exception: Other  0.05 sec