remove upper bound on sympy version; bugfix: import dill in forward_model


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/mystic/mystic@753 968178ea-60bd-409e-af13-df8a517b6005
silent assertions for test_SOW2 and test_compound_termination
use random_seed for test_constraints and test_solver_constraints


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/mystic/mystic@754 968178ea-60bd-409e-af13-df8a517b6005
Merge branch 'master' of https://github.com/uqfoundation/mystic