Updates needed to workflows

[jdechalendar]

• [x] Update Makefile to make bulk dataset easier to reproduce -- see #47
• [x] Update workflow to save deltas here -- done in #44
• [x] #40
• [x] Merge six month datasets -- done in #42
• [x] Extra timesteps: are these added by the rolling window cleaner? Possibly related to #30
• [x] Store gridemissions version in name of dataset that is uploaded to aws (processed.v0.1.7.tar.gz). Check version on load. Also store date it was created? -- Done in 1c8a883
• [ ] Add a parquet file with the full dataset for users who just want to deal with one file
  • [ ] Consider merging the six month files into one dataset at the beginning of the workflow and running that