Clean up sr-io (#3609)

* Move trait `Printable` into `sr-primitives`

* Cleanup runtime io trie_root interfaces

* Remove last generic bits from sr-io interface

* Fix srml-sudo after master merge

* Fix benchmarks

* Runtime bump

substrate/srml/support/test/tests/final_keys.rs

@@ -14,7 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-use runtime_io::{with_externalities, Blake2Hasher};
+use runtime_io::with_externalities;
+use primitives::Blake2Hasher;
 use support::{StorageValue, StorageMap, StorageLinkedMap, StorageDoubleMap};
 use support::storage::unhashed;
 use codec::{Encode, Decode};