[BUG] openms/unimod.py

[fabianegli]

UnimodDatabase.modifications is a list but gets treated as if it was a dict.

pylint --disable all --enable E sdrf_pipelines
************* Module sdrf_pipelines.openms.unimod
sdrf_pipelines/openms/unimod.py:109:10: E1101: Instance of 'list' has no 'get' member (no-member)
sdrf_pipelines/openms/unimod.py:119:13: E1101: Instance of 'list' has no 'keys' member (no-member)
sdrf_pipelines/openms/unimod.py:126:10: E1101: Instance of 'list' has no 'get' member (no-member)
sdrf_pipelines/openms/unimod.py:139:10: E1101: Instance of 'list' has no 'get' member (no-member)

[ypriverol]

Already tackle in #148