Merge #2899. Thermo for inerts

Get thermochemistry even for non-reactive species during model initialization, to avoid crashing when loading libraries.

Author: rwest

examples/rmg/1,3-hexadiene/input.py

@@ -1,7 +1,7 @@
 # Data sources
 database(
     thermoLibraries = ['primaryThermoLibrary', 'GRI-Mech3.0'],
-    reactionLibraries = [],
+    reactionLibraries = ['NOx2018'],
     seedMechanisms = [],
     kineticsDepositories = ['training'], 
     kineticsFamilies = 'default',

rmgpy/rmg/main.py

@@ -648,8 +648,7 @@ def initialize(self, **kwargs):
         # Initialize reaction model
 
         for spec in self.initial_species:
-            if spec.reactive:
-                submit(spec, self.solvent)
+            submit(spec, self.solvent)
             if vapor_liquid_mass_transfer.enabled:
                 spec.get_liquid_volumetric_mass_transfer_coefficient_data()
                 spec.get_henry_law_constant_data()