Add data from all water companies in the UK

[AlexLipp]

Now that all other UK Water Companies have released live sewage spill data (all APIs and data here) we can extend SewageMap across the country! The back-end has now been updated to automatically calculate the downstream reaches (and the 'information' geojson which has a bit more detailed info about the spills) for every water company. The links to the cloudfront URLs for these files are in the table below. In keeping with previous behaviour we want to visualise the Downstream Impacted Reaches for Spills within last 48hrs. A 'last-updated' for each water-company is given, as well as a "global" timestamp which is when the update script was run.

When this has been incorporated we should update the info pop-up and then names of various things to reflect the national rather than just Thames picture. Will be great to get this visualised, will probably be the first actually good national map!

Data-table

Global update timestamp: global_timestamp.txt

Water Company	Downstream Impacted Reaches	Downstream Impact Information	Last Updated
Thames Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Anglian Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
United Utilities	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Welsh Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Southern Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Northumbrian Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Severn Trent Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Wessex Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
Yorkshire Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp
SouthWest Water	Current spills; Spills within last 48hrs	Current spills; Spills within last 48hrs	Timestamp