feat(build): use prettyplease to format output (#890) (#904)

tonic-build/Cargo.toml

@@ -15,6 +15,7 @@ repository = "https://github.com/hyperium/tonic"
 version = "0.6.2"
 
 [dependencies]
+prettyplease = {version = "0.1"}
 proc-macro2 = "1.0"
 prost-build = {version = "0.9", optional = true}
 quote = "1.0"
@@ -22,9 +23,8 @@ syn = "1.0"
 
 [features]
 compression = []
-default = ["transport", "rustfmt", "prost"]
+default = ["transport", "prost"]
 prost = ["prost-build"]
-rustfmt = []
 transport = []
 
 [package.metadata.docs.rs]