Set version to 0.3.0

Author: github-actions[bot]

Project.toml

@@ -1,7 +1,7 @@
 name = "SymbolicNeuralNetworks"
 uuid = "aed23131-dcd0-47ca-8090-d21e605652e3"
 authors = ["Michael Kraus"]
-version = "0.2.0"
+version = "0.3.0"
 
 [deps]
 AbstractNeuralNetworks = "60874f82-5ada-4c70-bd1c-fa6be7711c8a"