clean up 2015 in tests

Author: csmoe

core/tests/lib.rs

@@ -1,4 +1,4 @@
-extern crate witnet_core as core;
+use witnet_core as core;
 
 use crate::core::greetings;
 

crypto/tests/lib.rs

@@ -1,4 +1,4 @@
-extern crate witnet_crypto as crypto;
+use witnet_crypto as crypto;
 
 use crate::crypto::greetings;
 

data_structures/tests/lib.rs

@@ -1,4 +1,4 @@
-extern crate witnet_data_structures as data_structures;
+use witnet_data_structures as data_structures;
 
 use crate::data_structures::greetings;
 

p2p/tests/lib.rs

@@ -1,4 +1,4 @@
-extern crate witnet_p2p as p2p;
+use witnet_p2p as p2p;
 
 use crate::p2p::greetings;
 

storage/tests/lib.rs

@@ -1,4 +1,4 @@
-extern crate witnet_storage as storage;
+use witnet_storage as storage;
 
 use crate::storage::greetings;