Upgrade to mbuild 0.16.0 after the bug fix affecting the test_gmso_charmm_writer.py unit test is fixed

[bc118]

There is currently a bug in mBuild 0.16.0 that makes the test_gmso_charmm_writer.py test file fail, specifically for the test below:

def test_write_inp_zeolite_non_othoganol_water_box_0_altered_under_hood(
    self, water
):

Also, we will have to remove sympy and replace it with symengine and/or python-symengine, like done in mosdef-hub/gmso#696 .

• Change they enviroment.yml and doc/environment_docs.yml files
• Change sympy.simplify to 'symengine.sympify'
• Or maybe just use the equation compare version directly from gmso, and remove the duplicate files from mosdef-gomc

I don't think symengine as a simplify function

After this is fixed in mBuild we can bump the install version of mBuild past 0.16.0, meaning the likely new version mBuild 0.16.x.