Remove unnecessary 'static lifetime

clippy emits a bunch of:

 warning: statics have by default a `'static` lifetime

Remove the unnecessary 'static lifetimes.

Author: tcharding

src/blockdata/transaction.rs

@@ -1662,7 +1662,7 @@ mod benches {
     use crate::hashes::hex::FromHex;
     use test::{black_box, Bencher};
 
-    const SOME_TX: &'static str = "0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000";
+    const SOME_TX: &str = "0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000";
 
     #[bench]
     pub fn bench_transaction_size(bh: &mut Bencher) {

src/util/key.rs

@@ -550,9 +550,9 @@ mod tests {
     fn test_key_serde() {
         use serde_test::{Configure, Token, assert_tokens};
 
-        static KEY_WIF: &'static str = "cVt4o7BGAig1UXywgGSmARhxMdzP5qvQsxKkSsc1XEkw3tDTQFpy";
-        static PK_STR: &'static str = "039b6347398505f5ec93826dc61c19f47c66c0283ee9be980e29ce325a0f4679ef";
-        static PK_STR_U: &'static str = "\
+        static KEY_WIF: &str = "cVt4o7BGAig1UXywgGSmARhxMdzP5qvQsxKkSsc1XEkw3tDTQFpy";
+        static PK_STR: &str = "039b6347398505f5ec93826dc61c19f47c66c0283ee9be980e29ce325a0f4679ef";
+        static PK_STR_U: &str = "\
             04\
             9b6347398505f5ec93826dc61c19f47c66c0283ee9be980e29ce325a0f4679ef\
             87288ed73ce47fc4f5c79d19ebfa57da7cff3aff6e819e4ee971d86b5e61875d\