Relax upper bounds

Author: hyperthunk

distributed-static.cabal

@@ -34,7 +34,7 @@ Library
   Exposed-Modules:     Control.Distributed.Static
   Build-Depends:       base >= 4.8 && < 5,
                        rank1dynamic >= 0.1 && < 0.5,
-                       containers >= 0.4 && < 0.6,
+                       containers >= 0.4 && < 0.7,
                        bytestring >= 0.10 && < 0.11,
                        binary >= 0.5 && < 0.9,
                        deepseq >= 1.3.0.1 && < 1.6