Make UnitfulAtomic only a test dependency

Author: mfherbst

Project.toml

@@ -8,7 +8,6 @@ AtomsBase = "a963bdd2-2df7-4f54-a1ee-49d51e6be12a"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
-UnitfulAtomic = "a7773ee8-282e-5fa2-be4e-bd808c38a91a"
 
 [compat]
 AtomsBase = "0.3"
@@ -20,6 +19,7 @@ julia = "1.6"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+UnitfulAtomic = "a7773ee8-282e-5fa2-be4e-bd808c38a91a"
 
 [targets]
-test = ["Test"]
+test = ["Test", "UnitfulAtomic"]