avoid PythonCall use before import

Author: mjohnson541

src/ReactionMechanismSimulator.jl

@@ -5,7 +5,12 @@ packages = keys(CondaPkg.current_packages())
 
 if !("rmg" in packages) && !("rmgmolecule" in packages)
     @info "missing rmg and rmgmolecule installing rmgmolecule..."
-    if !(v"3.7" <= PythonCall.C.python_version() && PythonCall.C.python_version() <= v"3.9")
+    if "python" in packages
+        py_version = VersionNumber(packages["python"][:version])
+    else
+        py_version = nothing
+    end
+    if py_version === nothing || !(v"3.7" <= py_version) && py_version <= v"3.9")
         @info "python version was not in 3.7-3.9 changing python version"
         CondaPkg.add("python"; version="3.9")
     end

src/rmstest.jl

@@ -6,7 +6,12 @@ packages = keys(CondaPkg.current_packages())
 
 if !("rmg" in packages) && !("rmgmolecule" in packages)
     @info "missing rmg and rmgmolecule installing rmgmolecule..."
-    if !(v"3.7" <= PythonCall.C.python_version() && PythonCall.C.python_version() <= v"3.9")
+    if "python" in packages
+        py_version = VersionNumber(packages["python"][:version])
+    else
+        py_version = nothing
+    end
+    if py_version === nothing || !(v"3.7" <= py_version) && py_version <= v"3.9")
         @info "python version was not in 3.7-3.9 changing python version"
         CondaPkg.add("python"; version="3.9")
     end