Update protobuf to version 2.3.0 (#904)

Initially I had hoped that the deprecated `#![allow(clippy)]` would no
longer be put into the generated rust files, but -- as of 2019-01-30 --
it still is (see [1] for details). Since we explicitly update the
protobuf files I decided to *manually edit the generated code* and
replace this with `#![allow(clippy:all)]`. Hopefully, by the time we do
the next upgrade, no such manual tweaking would be necessary anymore. I
think the benefit of a less polluted clippy output is worth it this
time.

[1]: https://github.com/stepancheg/rust-protobuf/pull/332

protocols/identify/Cargo.toml

@@ -17,7 +17,7 @@ libp2p-core = { version = "0.2.0", path = "../../core" }
 log = "0.4.1"
 multiaddr = { package = "parity-multiaddr", version = "0.1.0", path = "../../misc/multiaddr" }
 parking_lot = "0.7"
-protobuf = "2.0.2"
+protobuf = "2.3"
 smallvec = "0.6"
 tokio-codec = "0.1"
 tokio-io = "0.1.0"

protocols/identify/regen_structs_proto.sh

@@ -5,7 +5,7 @@
 sudo docker run --rm -v `pwd`:/usr/code:z -w /usr/code rust /bin/bash -c " \
     apt-get update; \
     apt-get install -y protobuf-compiler; \
-    cargo install --version 2.0.2 protobuf-codegen; \
+    cargo install --version 2.3.0 protobuf-codegen; \
     protoc --rust_out . structs.proto"
 
 sudo chown $USER:$USER *.rs

protocols/identify/src/structs_proto.rs

@@ -1,9 +1,9 @@
-// This file is generated by rust-protobuf 2.0.2. Do not edit
+// This file is generated by rust-protobuf 2.3.0. Do not edit
 // @generated
 
 // https://github.com/Manishearth/rust-clippy/issues/702
 #![allow(unknown_lints)]
-#![allow(clippy)]
+#![allow(clippy::all)]
 
 #![cfg_attr(rustfmt, rustfmt_skip)]
 
@@ -31,8 +31,8 @@ pub struct Identify {
     observedAddr: ::protobuf::SingularField<::std::vec::Vec<u8>>,
     protocols: ::protobuf::RepeatedField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
-    cached_size: ::protobuf::CachedSize,
+    pub unknown_fields: ::protobuf::UnknownFields,
+    pub cached_size: ::protobuf::CachedSize,
 }
 
 impl Identify {