check in rpc_capnp.rs and rpc_twoparty_capnp.rs, to avoid build-time dependency on capnp tool

Author: dwrensha

capnp-rpc/Cargo.toml

@@ -3,7 +3,6 @@
 name = "capnp-rpc"
 version = "0.12.0"
 authors = [ "David Renshaw <dwrenshaw@sandstorm.io>" ]
-build = "build.rs"
 license = "MIT"
 description = "implementation of the Cap'n Proto remote procedure call protocol"
 repository = "https://github.com/dwrensha/capnproto-rust"
@@ -19,9 +18,6 @@ readme = "README.md"
 name = "capnp_rpc"
 path = "src/lib.rs"
 
-[build-dependencies]
-capnpc = { version = "0.12.0", path = "../capnpc" }
-
 [dependencies]
 futures = "0.3.0"
 capnp-futures = { version = "0.12.0", path = "../capnp-futures" }