Make provider pub so consumer can access it, and don't require all providers to be default

src/client/mod.rs

@@ -27,11 +27,12 @@ pub struct Client<P: Provider> {
     /// Redirect URI.
     pub redirect_uri: Option<String>,
 
-    provider: P,
+    /// The provider.
+    pub provider: P,
 }
 
-impl<P: Provider> Client<P> {
-    /// Creates a client.
+impl<P: Provider + Default> Client<P> {
+     /// Creates a client.
     ///
     /// # Examples
     ///
@@ -48,7 +49,9 @@ impl<P: Provider> Client<P> {
     pub fn new(client_id: String, client_secret: String, redirect_uri: Option<String>) -> Self {
         Client::with_provider(client_id, client_secret,  P::default(), redirect_uri)
     }
+}
 
+impl<P: Provider> Client<P> {
     /// Creates a client with a given Provider. Use when the provider needs non-default Initialization.
     pub fn with_provider(
             client_id: String, 

src/provider.rs

@@ -3,7 +3,7 @@
 use token::{Token, Lifetime, Bearer, Static, Refresh};
 
 /// OAuth 2.0 providers.
-pub trait Provider: Default {
+pub trait Provider {
     /// The lifetime of tokens issued by the provider.
     type Lifetime: Lifetime;