imp(serde):use proc_macros and serde-derive

With Rust 1.15, proc macros have been stabilized. Therefore
custom build scripts are not required anymore.

This commit removes all the previous machinery and the
need for nightly.

src/build.rs

@@ -1,26 +0,0 @@
-#[cfg(feature = "with-serde-codegen")]
-mod inner {
-    extern crate serde_codegen;
-
-    use std::env;
-    use std::path::Path;
-
-    pub fn main() {
-        let out_dir = env::var_os("OUT_DIR").unwrap();
-
-        let src = Path::new("src/lib.rs.in");
-        let dst = Path::new(&out_dir).join("lib.rs");
-
-        serde_codegen::expand(&src, &dst).unwrap();
-    }
-}
-
-#[cfg(not(feature = "with-serde-codegen"))]
-mod inner {
-    pub fn main() {
-    }
-}
-
-pub fn main() {
-    inner::main()
-}

src/lib.rs

@@ -35,8 +35,6 @@
 //! authorize future API requests to the same scopes.
 //!
 //! ```test_harness,no_run
-//! #![cfg_attr(feature = "nightly", feature(proc_macro))]
-//! #[cfg(feature = "nightly")]
 //! #[macro_use]
 //! extern crate serde_derive;
 //! 
@@ -67,10 +65,41 @@
 //! # }
 //! ```
 //!
-#![cfg_attr(feature = "nightly", feature(proc_macro))]
+#[macro_use]
+extern crate serde_derive;
 
-#[cfg(feature = "nightly")]
-include!("lib.rs.in");
+extern crate serde;
+extern crate serde_json;
+
+extern crate base64;
+extern crate chrono;
+extern crate openssl;
+extern crate hyper;
+#[cfg(test)]
+extern crate log;
+#[cfg(test)]
+extern crate yup_hyper_mock;
+extern crate url;
+extern crate itertools;
+
+mod authenticator;
+mod authenticator_delegate;
+mod device;
+mod helper;
+mod installed;
+mod refresh;
+mod service_account;
+mod storage;
+mod types;
+
+pub use device::{GOOGLE_DEVICE_CODE_URL, DeviceFlow};
+pub use refresh::{RefreshFlow, RefreshResult};
+pub use types::{Token, FlowType, ApplicationSecret, ConsoleApplicationSecret, Scheme, TokenType};
+pub use installed::{InstalledFlow, InstalledFlowReturnMethod};
+pub use storage::{TokenStorage, NullStorage, MemoryStorage, DiskTokenStorage};
+pub use authenticator::{Authenticator, Retry, GetToken};
+pub use authenticator_delegate::{AuthenticatorDelegate, DefaultAuthenticatorDelegate, PollError,
+                                 PollInformation};
+pub use helper::*;
+pub use service_account::*;
 
-#[cfg(feature = "with-serde-codegen")]
-include!(concat!(env!("OUT_DIR"), "/lib.rs"));

src/lib.rs.in

@@ -1,38 +0,0 @@
-#[cfg(feature = "nightly")]
-#[macro_use]
-extern crate serde_derive;
-
-extern crate serde;
-extern crate serde_json;
-
-extern crate base64;
-extern crate chrono;
-extern crate openssl;
-extern crate hyper;
-#[cfg(test)]
-extern crate log;
-#[cfg(test)]
-extern crate yup_hyper_mock;
-extern crate url;
-extern crate itertools;
-
-mod authenticator;
-mod authenticator_delegate;
-mod device;
-mod helper;
-mod installed;
-mod refresh;
-mod service_account;
-mod storage;
-mod types;
-
-pub use device::{GOOGLE_DEVICE_CODE_URL, DeviceFlow};
-pub use refresh::{RefreshFlow, RefreshResult};
-pub use types::{Token, FlowType, ApplicationSecret, ConsoleApplicationSecret, Scheme, TokenType};
-pub use installed::{InstalledFlow, InstalledFlowReturnMethod};
-pub use storage::{TokenStorage, NullStorage, MemoryStorage, DiskTokenStorage};
-pub use authenticator::{Authenticator, Retry, GetToken};
-pub use authenticator_delegate::{AuthenticatorDelegate, DefaultAuthenticatorDelegate, PollError,
-                                 PollInformation};
-pub use helper::*;
-pub use service_account::*;