Always print help message if `-h` or `--help` flags passed

Since we've set up required arguments, 'getopts' fails fast and
complains about missing required args even if the only one used was `-h`
or `--help`. Why should you care about required arguments? You wanted
help in the first place, how are you going to know?

Thankfully, this message from 'prasannavl' pointed me in the right
direction:
https://github.com/rust-lang-nursery/getopts/issues/46#issuecomment-343842947

If there's an option parse failure, we can just look for the help flags
in the args vec to see if we should display the help.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index 32134c2..55f8093 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -64,6 +64,13 @@ fn run() -> Result<()> {
     let opt_matches = match opts.parse(&args[1..]) {
         Ok(m) => m,
         Err(f) => {
+            if args.contains(&"-h".to_owned()) ||
+                    args.contains(&"--help".to_owned()) {
+                print_usage(opts);
+
+                return Ok(());
+            }
+
             eprintln!("meetup-find-events-rss: error: {}", f.to_string());
             exit(1);
         },