csdms compliant bmi (cont. 2)

[DirkEilander]

After #74 we need a second iteration to make glofrim follow the bmi convention as stated here https://bmi-spec.readthedocs.io/en/latest/bmi.lang.py.html We can use this bmi-tester to check the compatibility https://github.com/csdms/bmi-tester Glofrim addition like the additions like the two-step initialization and grid method should be build on top of this.