make muq optional (like the docs say!) and add a helpful msg if missing

Author: JacksonBurns

environment.yml

@@ -79,7 +79,6 @@ dependencies:
   - conda-forge::gprof2dot
   - conda-forge::numdifftools
   - conda-forge::quantities
-  - conda-forge::muq
   - conda-forge::lpsolve55
   - conda-forge::ringdecomposerlib-python
 

rmgpy/rmg/main.py

@@ -1274,8 +1274,11 @@ def run_uncertainty_analysis(self):
         if self.uncertainty is not None and self.uncertainty["global"]:
             try:
                 import muq
-            except ImportError:
-                logging.error("Unable to import MUQ. Skipping global uncertainty analysis.")
+            except ImportError as ie:
+                logging.error(
+                    f"Skipping global uncertainty analysis! Unable to import MUQ (original error: {str(ie)})."
+                    "Install muq with 'conda install -c conda-forge muq'."
+                )
                 self.uncertainty["global"] = False
             else:
                 import re