Replace methods with more flexible endpoints

tests/ui/resource/unknown_method.rs

@@ -0,0 +1,11 @@
+#[macro_use]
+extern crate gotham_restful;
+
+#[derive(Resource)]
+#[resource(read_any)]
+struct FooResource;
+
+#[read_all]
+fn read_all() {}
+
+fn main() {}

tests/ui/resource/unknown_method.stderr

@@ -0,0 +1,8 @@
+error[E0412]: cannot find type `read_any___gotham_restful_endpoint` in this scope
+ --> $DIR/unknown_method.rs:5:12
+  |
+5 | #[resource(read_any)]
+  |            ^^^^^^^^ help: a struct with a similar name exists: `read_all___gotham_restful_endpoint`
+...
+8 | #[read_all]
+  | ----------- similarly named struct `read_all___gotham_restful_endpoint` defined here