Make python_scripts_executable test more deterministic
Make python_scripts_executable test more deterministic

It was failing on OSX due to file searching occuring in a different
order, and frankly we can predict the path of the script dir, so
let's use that instead of searching for it.

doghrim/fpm,tjyang/fpm,mildred/fpm,doghrim/fpm,schatt/fpm,fetep/fpm,linearregression/fpm,rbramwell/fpm,rbramwell/fpm,elvido/fpm,cturra/fpm,tjyang/fpm,pskrz/fpm,wyaeld/fpm,virtkick/fpm,virtkick/fpm,josephfrazier/fpm,josephfrazier/fpm,gearmover/fpm,tjyang/fpm,snailwalker/fpm,vi4m/fpm,mildred/fpm,vi4m/fpm,jerizm/fpm,jerizm/fpm,mildred/fpm,paul-krohn/fpm,fetep/fpm,godp1301/fpm,gearmover/fpm,paul-krohn/fpm,dischord01/fpm,pskrz/fpm,wyaeld/fpm,wyaeld/fpm,sideci-sample/sideci-sample-fpm,joseph-onsip/fpm,doghrim/fpm,schatt/fpm,sideci-sample/sideci-sample-fpm,linearregression/fpm,hlawrenz/fpm,josephfrazier/fpm,tjyang/fpm,dischord01/fpm,vi4m/fpm,pskrz/fpm,paul-krohn/fpm,paul-krohn/fpm,fetep/fpm,dischord01/fpm,doghrim/fpm,snailwalker/fpm,joseph-onsip/fpm,Tapjoy/fpm,Tapjoy/fpm,cturra/fpm,cturra/fpm,godp1301/fpm,cturra/fpm,elvido/fpm,rbramwell/fpm,wyaeld/fpm,dischord01/fpm,joseph-onsip/fpm,mzaccari/fpm,hlawrenz/fpm,Tapjoy/fpm,fetep/fpm,virtkick/fpm,vi4m/fpm,rbramwell/fpm,snailwalker/fpm,joseph-onsip/fpm,mildred/fpm,linearregression/fpm,Tapjoy/fpm,godp1301/fpm,elvido/fpm,hlawrenz/fpm,gearmover/fpm,elvido/fpm,schatt/fpm,mzaccari/fpm,hlawrenz/fpm,godp1301/fpm,pskrz/fpm,sideci-sample/sideci-sample-fpm,jerizm/fpm,jerizm/fpm,josephfrazier/fpm,schatt/fpm,mzaccari/fpm,mzaccari/fpm,virtkick/fpm,gearmover/fpm,linearregression/fpm,snailwalker/fpm