Problem with pep8 in WMAgent Dev

Hi @BrunoCoimbra @ticoann

When I try to run "pep8" within our deployment I get an error
```
[dmwm@72d561e8d903 WMCore]$ pep8
bash: /home/dmwm/unittestdeploy/wmagent/1.1.3.pre5/sw/slc6_amd64_gcc493/external/py2-pep8/1.7.0-comp2/bin/pep8: /build/dmwmbld/srv/state/dmwmbld/builds/comp_gcc493/w/slc6_amd64_gcc493/extern: bad interpreter: No such file or directory
```

This comes from the fact that the python it's trying to use at the start of `which pep8` is this:
#!/build/dmwmbld/srv/state/dmwmbld/builds/comp_gcc493/w/slc6_amd64_gcc493/external/python/2.7.13/bin/python

If I replace this with the standard /usr/bin/env python , everything is OK. Can you fix the RPMs please?