src: Fix clippy from_over_into warnings

Nightly clippy strikes again.

`Request` and `Response` ignore this, because it makes the docs worse.
See rust-lang/rust-clippy#6607

Switched `RequestBuilder` -> `Request` to use `From`.

Author: Fishrock123

src/request.rs

@@ -382,6 +382,7 @@ impl From<http::Request> for Request {
     }
 }
 
+#[allow(clippy::from_over_into)]
 impl Into<http::Request> for Request {
     /// Converts a `surf::Request` to an `http::Request`.
     fn into(self) -> http::Request {

src/request_builder.rs

@@ -288,9 +288,9 @@ impl Future for RequestBuilder {
     }
 }
 
-impl Into<Request> for RequestBuilder {
+impl From<RequestBuilder> for Request {
     /// Converts a `surf::RequestBuilder` to a `surf::Request`.
-    fn into(self) -> Request {
-        self.build()
+    fn from(builder: RequestBuilder) -> Request {
+        builder.build()
     }
 }

src/response.rs

@@ -321,6 +321,7 @@ impl From<http::Response> for Response {
     }
 }
 
+#[allow(clippy::from_over_into)]
 impl Into<http::Response> for Response {
     fn into(self) -> http::Response {
         self.res