Remove unused key types sr25 and ed25 (#3659)

* Remove unused key types sr25 and ed25.

* Restore in specific files to fix build.

* Fix runtime tests

* Fix keystore test

* Revert typo

* Move keytypes to primitives/src/testing.rs

* More missed items.

* Getting close now.

* Fix example in documentation.

* Update core/application-crypto/src/ed25519.rs

* Update core/application-crypto/src/sr25519.rs

* Bump impl version.

substrate/core/test-runtime/src/lib.rs

@@ -25,7 +25,14 @@ pub mod system;
 use rstd::{prelude::*, marker::PhantomData};
 use codec::{Encode, Decode, Input, Error};
 
-use primitives::{Blake2Hasher, OpaqueMetadata};
+use primitives::{
+	Blake2Hasher,
+	OpaqueMetadata,
+	testing::{
+		ED25519,
+		SR25519,
+	}
+};
 use app_crypto::{ed25519, sr25519, RuntimeAppPublic};
 pub use app_crypto;
 use trie_db::{TrieMut, Trie};
@@ -47,7 +54,7 @@ use sr_primitives::{
 	},
 };
 use runtime_version::RuntimeVersion;
-pub use primitives::{hash::H256, crypto::key_types};
+pub use primitives::{hash::H256};
 #[cfg(any(feature = "std", test))]
 use runtime_version::NativeVersion;
 use runtime_support::{impl_outer_origin, parameter_types};
@@ -446,9 +453,9 @@ fn code_using_trie() -> u64 {
 
 impl_opaque_keys! {
 	pub struct SessionKeys {
-		#[id(key_types::ED25519)]
+		#[id(ED25519)]
 		pub ed25519: ed25519::AppPublic,
-		#[id(key_types::SR25519)]
+		#[id(SR25519)]
 		pub sr25519: sr25519::AppPublic,
 	}
 }