Update upper bound limit of base64-bytestring (#1383)

Author: mimi1vx

servant-client-core/servant-client-core.cabal

@@ -71,7 +71,7 @@ library
   build-depends:
       aeson                 >= 1.4.1.0  && < 1.6
     , base-compat           >= 0.10.5   && < 0.12
-    , base64-bytestring     >= 1.0.0.1  && < 1.2
+    , base64-bytestring     >= 1.0.0.1  && < 1.3
     , exceptions            >= 0.10.0   && < 0.11
     , free                  >= 5.1      && < 5.2
     , http-media            >= 0.7.1.3  && < 0.9