Re-running with more complete data

[jessicaguo]

@egreich After merging #31, Emma to:

• Rerun / modify all .R in scripts/
• Pay special attention to 04-export-clean.R, renaming of variables and possibly removing study filtering steps
• If warranted, create new 00_data_prep.R in models/01-test/Ricker to convert generalized ET .Rdata file to coded file ready for model (other option is to perform steps, if not too numerous, in 01-run-model.R