Provide request timeout for blocking API (#764)

src/blocking/request.rs

@@ -1,5 +1,6 @@
 use std::fmt;
 use std::convert::TryFrom;
+use std::time::Duration;
 
 use base64::encode;
 use serde::Serialize;
@@ -84,6 +85,18 @@ impl Request {
         &mut self.body
     }
 
+    /// Get the timeout.
+    #[inline]
+    pub fn timeout(&self) -> Option<&Duration> {
+        self.inner.timeout()
+    }
+
+    /// Get a mutable reference to the timeout.
+    #[inline]
+    pub fn timeout_mut(&mut self) -> &mut Option<Duration> {
+        self.inner.timeout_mut()
+    }
+
     /// Attempts to clone the `Request`.
     ///
     /// None is returned if a body is which can not be cloned. This can be because the body is a
@@ -300,6 +313,18 @@ impl RequestBuilder {
         self
     }
 
+    /// Enables a request timeout.
+    ///
+    /// The timeout is applied from the when the request starts connecting
+    /// until the response body has finished. It affects only this request
+    /// and overrides the timeout configured using `ClientBuilder::timeout()`.
+    pub fn timeout(mut self, timeout: Duration) -> RequestBuilder {
+        if let Ok(ref mut req) = self.request {
+            *req.timeout_mut() = Some(timeout);
+        }
+        self
+    }
+
     /// Modify the query string of the URL.
     ///
     /// Modifies the URL of this request, adding the parameters provided.