providers: Use references for field access

src/provider/github.rs

@@ -88,20 +88,20 @@ impl Provider for Github {
         })
     }
 
-    fn name(&self) -> String {
+    fn name(&self) -> &str {
-        String::from(PROVIDER_NAME)
+        PROVIDER_NAME
     }
 
-    fn filter(&self) -> Filter {
+    fn filter(&self) -> &Filter {
-        self.filter.clone()
+        &self.filter
     }
 
     fn secret_token(&self) -> &auth::AuthToken {
         &self.secret_token
     }
 
-    fn auth_header_key() -> String {
+    fn auth_header_key() -> &'static str {
-        "token".to_string()
+        "token"
     }
 
     fn get_user_projects(

src/provider/gitlab.rs

@@ -105,20 +105,20 @@ impl Provider for Gitlab {
         })
     }
 
-    fn name(&self) -> String {
+    fn name(&self) -> &str {
-        String::from(PROVIDER_NAME)
+        PROVIDER_NAME
     }
 
-    fn filter(&self) -> Filter {
+    fn filter(&self) -> &Filter {
-        self.filter.clone()
+        &self.filter
     }
 
     fn secret_token(&self) -> &auth::AuthToken {
         &self.secret_token
     }
 
-    fn auth_header_key() -> String {
+    fn auth_header_key() -> &'static str {
-        "bearer".to_string()
+        "bearer"
     }
 
     fn get_user_projects(

src/provider/mod.rs

@@ -122,10 +122,10 @@ pub trait Provider {
     where
         Self: Sized;
 
-    fn name(&self) -> String;
+    fn name(&self) -> &str;
-    fn filter(&self) -> Filter;
+    fn filter(&self) -> &Filter;
     fn secret_token(&self) -> &auth::AuthToken;
-    fn auth_header_key() -> String;
+    fn auth_header_key() -> &'static str;
 
     fn get_user_projects(
         &self,