1.15.0

• add Heilbronn to abfall.io wizard (thanks @dergeberl)
• add source for NAWMA (thanks @TheNoctambulist)
• add source egn_abfallkalender_de (thanks @audacity363)
• remove source abfall_kreis_tuebingen_de (they switched to awido_de)
• improve city-only support for awido_de (no need to specify street for city-only sources)
• add eBe Essen to abfall_io wizard (thanks @Z0mbiel0ne)
• minor bugfixes (thanks @rikroe)
• add Ludwigshafen am Rhein to abfall_io wizard (thanks @FHeilmann)
• add source for Christchurch City Council, NZ (thanks @codyc1515)
• add source for York, UK (thanks @spamoom)
• add source for Würzburg, Germany (thanks @rikroe)