Readd the --force flag to the CLI

This was still present in the lib and options parsing,
but was not in the Clap args list for some reason.

src/main.rs

@@ -194,6 +194,9 @@ fn main() {
         .arg(Arg::with_name("fix")
             .help("Enable error recovery")
             .long("fix"))
+        .arg(Arg::with_name("force")
+            .help("Write the output even if it is larger than the input")
+            .long("force"))
         .arg(Arg::with_name("zopfli")
             .help("Use the slower but better compressing Zopfli algorithm, overrides zlib-specific options")
             .short("Z")