0.42

• Introduction of a new taf keyword for retrieving TAF data - see issues #18 and #19
• By default, the metar keyword now only returns METAR data and the taf keyword only returns TAF data
• Add the full keyword to both commands in order to receive both METAR and TAF data responses via a single command, e.g. metar EDDF full or taf EDDF full both return METAR and TAF data for EDDF