Update clippy

The clippy version we were using, doesn't even run on the current
nightly.

Author: rnestler

Cargo.toml

@@ -38,7 +38,7 @@ router = "^0.2"
 error-type = "^0.1"
 serde_json = "^0.8"
 spaceapi = "^0.4.2"
-clippy = {version = "^0.0.87", optional = true}
+clippy = {version = "^0.0.139", optional = true}
 
 [features]
 unstable = ["clippy"]