fix get_tradeId in order class

switch to setuptools_scm versioning

fxcmpy v1.2.1:

subscribing to price updates adds snapshot to price collection. no need to
wait for first update anymore

fxcmpy v1.2.0:

all variables can be read from the config file
config file is read and parsed only once
config file now accepts strings with and without quotation marks
config file and log file can no longer be the same file
check token for correct length (40 characters)