Merge pull request #428 from SciML/compathelper/new_version/2021-08-10-00-45-24-239-20298990

CompatHelper: bump compat for "Symbolics" to "3" for package perturbation

Author: ChrisRackauckas

tutorials/perturbation/Project.toml

@@ -12,4 +12,4 @@ ModelingToolkit = "5.17, 6"
 Plots = "1.16"
 SciMLTutorials = "0.9"
 SymbolicUtils = "0.11, 0.12, 0.13"
-Symbolics = "0.1, 1, 2"
+Symbolics = "0.1, 1, 2, 3"