Write tests

[karbassi]

To bring this package up to standards, we need to have tests for each API call.

The API docs have definitions of what is required and optional and what is expected.

For example: https://dev.netatmo.com/apidocumentation/weather#getpublicdata

Name	Type	Required	Default	Description
lat_ne	number	Y		latitude of the north east corner of the requested area. -85 <= lat_ne <= 85 and lat_ne>lat_sw
lon_ne	number	Y		Longitude of the north east corner of the requested area. -180 <= lon_ne <= 180 and lon_ne>lon_sw
lat_sw	number	Y		latitude of the south west corner of the requested area. -85 <= lat_sw <= 85
lon_sw	number	Y		Longitude of the south west corner of the requested area. -180 <= lon_sw <= 180
required_data	string	N	''	To filter stations based on relevant measurements you want (e.g. rain will only return stations with rain gauges). You can find all measurements available on the Thermostat page.
filter	boolean	N	false	True to exclude station with abnormal temperature measures.

[karbassi]

@floetenbaer is this something you can take on?

[floetenbaer]

@karbassi : uploaded new branch: feature/unit-test. What do you think about it?