Merge pull request #110 from lucab/ups/update-ring

cargo: bump ring to 0.11
diff --git a/Cargo.toml b/Cargo.toml
index f4a9d4f..ef2a49e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -37,7 +37,7 @@
 hyper = "0.10.10"
 itoa = "0.3"
 log = "0.3"
-ring = { version = "0.9.4", features = [ "rsa_signing" ] }
+ring = { version = "0.11", features = [ "rsa_signing" ] }
 serde = "1"
 serde_derive = "1"
 serde_json = "1"