Add emission results testing

[idelder]

Create a results test for some basic technology archetypes:

• Ordinary
• Curtailment
• Annual
• Flex
• Annual flex

Run a toy model and check that the following results are correctly accounted, by archetype and in total:

• Emissions
• Emissions costs
• Curtailment

[jeff-ws]

This is excellent work and it integrates/runs fine on my machine. Accept it! ;)