Remove the need to set PATH

[aradhakrishnanGFDL]

We need to make the following not required when calling catalog builder from the conda package.
setenv PATH ${PATH}:${CONDA_PREFIX}/lib/python3.1/site-packages/scripts/

Ref https://noaa-gfdl.github.io/CatalogBuilder/generation.html#using-conda-package

[aradhakrishnanGFDL]

@ceblanton you mentioned there is a way to do this in conda to add something to entry point or something like that. Can you start a PR with pointers to this? I can contribute.