Ensure that the project builds with Rust 1.57.0
Ensure that the project builds with Rust 1.57.0

I haven't fully decided on which Rust versions I want to commit to supporting, so this is somewhat arbitrary, but I'd rather people not get broken builds.                            		  		  		 	      			 	                 

not-an-aardvark/lucky-commit,not-an-aardvark/lucky-commit