Fix for the Test_value.test_value_set_r1_rit test of the _pipe_control.test_value unit test module.
This is a general fix for all unit test modules which use the
test_suite.unit_tests.value_testing_base.Value_testing_base base class. After the molecules,
residues and spins are manually created, the pipe_control.mol_res_spin.metadata_update() function is
called to make sure that all of the private and volatile metadata have been correctly created, so
that the other pipe_control.mol_res_spin module functions can operate correctly.
