python: Update to 2.7.15 (#8306)
python: Update to 2.7.15 (#8306)

2.7.14 does not compile with GCC 8, see https://bugs.python.org/issue33374.
matthiasdiener/spack,mfherbst/spack,krafczyk/spack,mfherbst/spack,LLNL/spack,tmerrick1/spack,krafczyk/spack,matthiasdiener/spack,LLNL/spack,tmerrick1/spack,tmerrick1/spack,matthiasdiener/spack,LLNL/spack,LLNL/spack,krafczyk/spack,iulian787/spack,iulian787/spack,mfherbst/spack,matthiasdiener/spack,tmerrick1/spack,iulian787/spack,mfherbst/spack,tmerrick1/spack,iulian787/spack,mfherbst/spack,matthiasdiener/spack,LLNL/spack,krafczyk/spack,krafczyk/spack,iulian787/spack