Nightly rustfmt

Format code with the nightly version of rustfmt, which sorts imports.

src/ledger.rs

@@ -1,6 +1,7 @@
 //! The `ledger` crate provides the foundational data structures for Proof-of-History,
 //! an ordered log of events in time.
 
+use entry::{next_tick, Entry};
 /// Each entry contains three pieces of data. The `num_hashes` field is the number
 /// of hashes performed since the previous entry.  The `id` field is the result
 /// of hashing `id` from the previous entry `num_hashes` times.  The `event`
@@ -12,9 +13,7 @@
 /// Though processing power varies across nodes, the network gives priority to the
 /// fastest processor. Duration should therefore be estimated by assuming that the hash
 /// was generated by the fastest processor at the time the entry was recorded.
-
 use hash::Hash;
-use entry::{next_tick, Entry};
 use rayon::prelude::*;
 
 /// Verifies the hashes and counts of a slice of events are all consistent.