Switching to regex_lite and s optimization level - 2x binary size reduction.

src/nyan_system.rs

@@ -251,7 +251,7 @@ pub fn bzzpss_dev_encrypted(dev_name: &str) -> Result<bool, ExecCommandError> {
 
 //const TMP_ROOT: &str = "/mnt/bee-root";
 pub fn list_bzzpss_snaps(snaps_dir: &str) -> Result<Vec<String>, ExecCommandError> {
-    use regex::Regex;
+    use regex_lite::Regex;
     use std::path::Path;
 
     // root snapshoot in a form of bzz-yyyy-mm-ddTHH-MM-SS