Present/past weather groups might be using incorrect table lookups in some cases

[aothompson]

Here is an example synop I'm working with:

AAXX 21121
15001 07415 32931 10103 21090 39765 42250 57020 60071 72006 82110 91155
333 10178 21073 34101 55055 00010 20003 30002 50001 60004
60035 70500 83145 81533 91008 91111
444 18031 22053

This message has a weather indicator of 7. According to the WMO Manual on Codes, this indicates present weather should be encoded using tables 4680 and 4531. However, the output for present and past weather groups when running the decoder is the following:

'present_weather': {'value': 20,
'_table': '4677',
'time_before_obs': {'value': 6, 'unit': 'h'}},
'past_weather': [{'value': 0, '_table': '4561'},
{'value': 6, '_table': '4561'}],

After running some tests with different values of the weather indicator, it looks like it is just always doing weather lookups in table 4677 and 4561 regardless of what is specified.

Also, according to the WMO Code manual, if the weather indicator is coded as 2,3,5, or 6, that would suggest the present/past weather groups are omitted. In the above message, I tried changing the indicator to these values and present/past weather groups were still being returned. Idk if this is a bug per se but I thought it was worth mentioning

[tdbabas]

Fix applied in latest release (0.1.6)