libimagtimeui: Deny warnings and fix denied

Signed-off-by: Gavin Thomas Claugus <gclaugus@gmail.com>

libimagtimeui/src/cli.rs

@@ -1,4 +1,4 @@
-use clap::{Arg, ArgMatches, App, SubCommand};
+use clap::Arg;
 
 pub fn build_datetime_cli_component<'a, 'b>() -> Arg<'a, 'b> {
     Arg::with_name(datetime_arg_name())

libimagtimeui/src/lib.rs

@@ -1,3 +1,17 @@
+#![deny(
+    non_camel_case_types,
+    non_snake_case,
+    path_statements,
+    trivial_numeric_casts,
+    unstable_features,
+    unused_allocation,
+    unused_import_braces,
+    unused_imports,
+    unused_mut,
+    unused_qualifications,
+    while_true,
+)]
+
 extern crate chrono;
 extern crate clap;
 extern crate regex;