Reformat imports to a consistent style for imports

rustfmt.toml configuration:
  imports_granularity = "One"
  group_imports = "One"

metrics/src/counter.rs

@@ -211,13 +211,15 @@ impl Counter {
 }
 #[cfg(test)]
 mod tests {
-    use crate::counter::{Counter, DEFAULT_LOG_RATE, DEFAULT_METRICS_RATE};
-    use log::Level;
-    use log::*;
-    use serial_test::serial;
-    use std::env;
-    use std::sync::atomic::Ordering;
-    use std::sync::{Once, RwLock};
+    use {
+        crate::counter::{Counter, DEFAULT_LOG_RATE, DEFAULT_METRICS_RATE},
+        log::{Level, *},
+        serial_test::serial,
+        std::{
+            env,
+            sync::{atomic::Ordering, Once, RwLock},
+        },
+    };
 
     fn get_env_lock() -> &'static RwLock<()> {
         static mut ENV_LOCK: Option<RwLock<()>> = None;

metrics/src/lib.rs

@@ -3,7 +3,6 @@ pub mod counter;
 pub mod datapoint;
 mod metrics;
 pub use crate::metrics::{flush, query, set_host_id, set_panic_hook, submit};
-
 use std::sync::Arc;
 
 /// A helper that sends the count of created tokens as a datapoint.