Removed sklearn import in __init__.py as this does not seem to be needed after...

Removed sklearn import in __init__.py as this does not seem to be needed after upgrading Ubuntu from 14.04 to 16.04.
Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

tests/__init__.py

@@ -27,7 +27,6 @@
 """Unit test package for testproject."""
 
 import os
-import sklearn  # noqa # avoids a static TLS ImportError during runtime of SICOR (when importing sklearn there)
 
 # set database host during tests
 db_host = 'localhost' if 'GMS_db_host' not in os.environ else os.environ['GMS_db_host']