Print errors to stderr instead of stdout

src/main.rs

@@ -144,7 +144,12 @@ fn main() {
             sync(&connection, get_auth_token(&config_dir), datasets, all)
         }
 
-        _ => println!("This feature is currently unimplemented."),
+        Subcommands::Ranking {
+            subcommand: RankingSC::Create,
+            dataset,
+        } => ranking_create(&connection, dataset),
+
+        _ => eprintln!("This feature is currently unimplemented."),
     }
 }
 

src/util.rs

@@ -10,12 +10,12 @@ pub const SECS_IN_DAY: u64 = SECS_IN_HR * 24;
 pub const SECS_IN_WEEK: u64 = SECS_IN_DAY * 7;
 
 pub fn error(msg: &str, code: i32) -> ! {
-    println!("\nERROR: {}", msg);
+    eprintln!("\nERROR: {}", msg);
     exit(code)
 }
 
 pub fn issue(msg: &str, code: i32) -> ! {
-    println!("\n{}", msg);
+    eprintln!("\n{}", msg);
     exit(code)
 }