add possibility of warning suppression

Author: lmiq

Project.toml

@@ -1,7 +1,7 @@
 name = "CellListMap"
 uuid = "69e1c6dd-3888-40e6-b3c8-31ac5f578864"
 authors = ["Leandro Martinez <[email protected]> and contributors"]
-version = "0.8.31"
+version = "0.8.32"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"

src/ParticleSystem.jl

@@ -1054,6 +1054,11 @@ end
 export PeriodicSystems
 module PeriodicSystems
     function __init__()
+        if haskey(ENV, "CELLLISTMAP_8.3_WARNING")
+            if ENV["CELLLISTMAP_8.3_WARNING"] == "false"
+                return
+            end
+        end
         @warn begin """\n
         
         Interface changes in v0.8.30, for `PeriodicSystems` submodule of CellListMap.
@@ -1072,7 +1077,7 @@ module PeriodicSystems
         The new `ParticleSystem` interface supports non-periodic systems, by
         not setting the `unitcell` field in the system (or set `unitcell = nothing`).
 
-        
+        Suppress this warning by setting: ENV["CELLLISTMAP_8.3_WARNING"] = "false"
 
         """ end _file=nothing _line=nothing
     end