Apply @cardoe suggested patches (see andersk#13)

Author: ctrlcctrlv

README.md

@@ -28,7 +28,7 @@ wrap your `enum` declaration inside the `enum_from_primitive!` macro.
 
 ```rust
 #[macro_use] extern crate enum_primitive;
-use enum_primitive::num_traits::FromPrimitive;
+use enum_primitive::FromPrimitive;
 
 enum_from_primitive! {
 #[derive(Debug, PartialEq)]

src/lib.rs

@@ -33,7 +33,7 @@
 //! ```
 //! #[macro_use]
 //! extern crate enum_primitive;
-//! use enum_primitive::num_traits::FromPrimitive;
+//! use enum_primitive::FromPrimitive;
 //!
 //! enum_from_primitive! {
 //! #[derive(Debug, PartialEq)]