Add external packages in RMG-Py to conda build's site-packages.
Add external packages in RMG-Py to conda build's site-packages.

pierrelb/RMG-Py,chatelak/RMG-Py,pierrelb/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py,chatelak/RMG-Py,nickvandewiele/RMG-Py