Provide python2-perf rather than python-perf
    
    The Python packaging guidelines[0] require that the package provide
    python2-perf, so this changes the sub-package name to python2-perf and
    adds the python_provides macro which changes the provides from:
    
    python-perf-4.15.0-0.rc8.git0.1.fc28.x86_64.rpm
    python-perf = 4.15.0-0.rc8.git0.1.fc28
    python-perf(x86-64) = 4.15.0-0.rc8.git0.1.fc28
    python2.7dist(perf) = 0.1
    python2dist(perf) = 0.1
    
    to:
    
    python-perf = 4.15.0-0.rc8.git0.1.fc28
    python-perf(x86-64) = 4.15.0-0.rc8.git0.1.fc28
    python2-perf = 4.15.0-0.rc8.git0.1.fc28
    python2-perf(x86-64) = 4.15.0-0.rc8.git0.1.fc28
    python2.7dist(perf) = 0.1
    python2dist(perf) = 0.1
    
    [0] https://fedoraproject.org/wiki/Packaging:Python#Provides