Allow containers-0.7 in network-transport-tests (fixes #457)

Author: LaurentRDC

packages/network-transport-tests/network-transport-tests.cabal

@@ -37,7 +37,7 @@ library
   -- other-modules:
   build-depends:       base >= 4.14 && < 5,
                        network-transport >= 0.4.1.0 && < 0.6,
-                       containers >= 0.6 && < 0.7,
+                       containers >= 0.6 && < 0.8,
                        bytestring >= 0.10 && < 0.13,
                        random >= 1.0 && < 1.3,
                        mtl >= 2.2.1 && < 2.4,