v1.2: Discussion on flight emissions and Gini coefficient

This solves #12. Methods are extended by a discussion around

• carbon emissions of short- vs long-haul flights
• indirect CO2 effects at higher altitudes, i.e. for longer flights
• atmosfair being the emission calculator that we used
• comparison to other emission calculators (ICAO, myclimate)

Additionally, the "sorted carbon emissions"-plot is now sorted from low to high emitting participants and the Gini coefficient is included.

v1.1: Merge pull request #10 from milankl/jefim

• Figure headers updated
• Minor chages in manuscript

Zenodo DOI added

This release is for zenodo DOI creation. No changes in master branch.

Reviewed for publication

This release contains

• Travel carbon emissions of EGU19, including map, "per country" and "per mode of transport" pie chart and sorted carbon emissions figure.
• Calculations for possible reduction scenarios.
• Summary, introduction and references

This release was reviewed by several colleagues and is now intended to be widely published. Future changes will be summarized in a new release.