CompatHelper: bump compat for JSON to 1, (keep existing compat)

Author: CompatHelper Julia

Project.toml

@@ -23,7 +23,7 @@ DataStructures = "0.15, 0.16, 0.17, 0.18"
 Distributions = "0.24, 0.25"
 ForwardDiff = "0.10.10"
 FunctionalCollections = "0.5"
-JSON = "0.20, 0.21"
+JSON = "0.20, 0.21, 1"
 MacroTools = "0.5"
 Parameters = "0.12"
 ReverseDiff = "1.4, 1.5"