fix clippy warnings

src/executor.rs

@@ -85,7 +85,7 @@ impl Executor {
 
     pub fn sleep(&mut self) {
         if self.sleep_period < self.max_sleep_period {
-            self.sleep_period = self.sleep_period + self.sleep_step;
+            self.sleep_period += self.sleep_step;
         }
 
         thread::sleep(Duration::from_secs(self.sleep_period));

src/postgres.rs

@@ -37,15 +37,11 @@ impl Postgres {
 
         let url = match database_url {
             Some(string_url) => string_url,
-            None => {
-                let url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
-
-                url
-            }
+            None => env::var("DATABASE_URL").expect("DATABASE_URL must be set"),
         };
 
         let connection =
-            PgConnection::establish(&url).expect(&format!("Error connecting to {}", url));
+            PgConnection::establish(&url).unwrap_or_else(|_| panic!("Error connecting to {}", url));
 
         Self {
             connection,
@@ -85,7 +81,7 @@ impl Postgres {
         self.connection.transaction::<Option<Task>, Error, _>(|| {
             let found_task = self.fetch_task();
 
-            if let None = found_task {
+            if found_task.is_none() {
                 return Ok(None);
             }
 

src/worker_pool.rs

@@ -36,7 +36,6 @@ impl WorkerThread {
 
     pub fn spawn_in_pool(name: String, restarts: u64) {
         let mut builder = thread::Builder::new().name(name.clone());
-        builder = builder;
 
         info!(
             "starting a worker thread {}, number of restarts {}",