Remove Headers from the public API. (#224)

It turns out Headers is actually an internal-only API. None of the
user-facing types use it.

Unfortunately, making it unexported also required deleting the doctests,
since doctests can only run against a public interface.

src/header.rs

@@ -29,37 +29,16 @@ impl Header {
     }
 
     /// The header name.
-    ///
-    /// ```
-    /// let header = "X-Forwarded-For: 127.0.0.1"
-    ///     .parse::<ureq::Header>()
-    ///     .unwrap();
-    /// assert_eq!("X-Forwarded-For", header.name());
-    /// ```
     pub fn name(&self) -> &str {
         &self.line.as_str()[0..self.index]
     }
 
     /// The header value.
-    ///
-    /// ```
-    /// let header = "X-Forwarded-For: 127.0.0.1"
-    ///     .parse::<ureq::Header>()
-    ///     .unwrap();
-    /// assert_eq!("127.0.0.1", header.value());
-    /// ```
     pub fn value(&self) -> &str {
         &self.line.as_str()[self.index + 1..].trim()
     }
 
     /// Compares the given str to the header name ignoring case.
-    ///
-    /// ```
-    /// let header = "X-Forwarded-For: 127.0.0.1"
-    ///     .parse::<ureq::Header>()
-    ///     .unwrap();
-    /// assert!(header.is_name("x-forwarded-for"));
-    /// ```
     pub fn is_name(&self, other: &str) -> bool {
         self.name().eq_ignore_ascii_case(other)
     }
@@ -225,3 +204,13 @@ fn value_with_whitespace() {
     let h = "foo:      bar    ".parse::<Header>().unwrap();
     assert_eq!(h.value(), "bar");
 }
+
+#[test]
+fn name_and_value() {
+    let header: Header = "X-Forwarded-For: 127.0.0.1".parse().unwrap();
+    assert_eq!("X-Forwarded-For", header.name());
+    assert_eq!("127.0.0.1", header.value());
+    assert!(header.is_name("X-Forwarded-For"));
+    assert!(header.is_name("x-forwarded-for"));
+    assert!(header.is_name("X-FORWARDED-FOR"));
+}

src/unit.rs

@@ -7,16 +7,14 @@ use url::Url;
 #[cfg(feature = "cookies")]
 use cookie::Cookie;
 
+use crate::body::{self, BodySize, Payload, SizedReader};
 use crate::error::{Error, ErrorKind};
 use crate::header;
+use crate::header::{get_header, Header};
 use crate::resolve::ArcResolver;
+use crate::response::Response;
 use crate::stream::{self, connect_test, Stream};
 use crate::Agent;
-use crate::{
-    body::{self, BodySize, Payload, SizedReader},
-    header::get_header,
-};
-use crate::{Header, Response};
 
 /// A Unit is fully-built Request, ready to execute.
 ///