Create production parser for India as a whole

[systemcatch]

Currently we're assigning the combined renewable generation to 'unknown' which is fairly harsh, maybe we can come up with a better fixed intensity?

Let me know if anything needs to be adjusted so it doesn't show up on the map.

ref #1623

Little slow but it works.

(EM-env) chris@ThinkPad:~/electricitymap/parsers$ python IN.py 
fetch_production() -> 
{'datetime': datetime.datetime(2018, 11, 3, 17, 54, 43, 501302, tzinfo=tzfile('/usr/share/zoneinfo/Asia/Kolkata')), 'source': 'meritindia.in', 'storage': {}, 'production': {'unknown': 2470.0, 'gas': 7897.0, 'hydro': 23462.0, 'coal': 120586.0, 'nuclear': 4037.0}, 'zoneKey': 'IN'}

[brunolajoie]

Thanks Chris!
Can you update the default CO2 factor of "unknown" for india to

26 g/kWh
Source: Assumes 43% solar PV and 57% wind

And the capacity installed
Solar: 26GW
Wind: 34GW
Coal: 196GW
Hydro: 50GW
Gas: 25GW
Nuclear: 6.7GW
biomass: 9.4GW
Source: https://mercomindia.com/solar-indias-installed-power-capacity/

[systemcatch]

@brunolajoie happy with my additions?

[brunolajoie]

Awesome!

[systemcatch]

I'll merge unless you guys have any further comments?

[corradio]

go ahead!