Provide getter for store path in Runtime object

src/runtime.rs

@@ -74,6 +74,10 @@ impl<'a> Runtime<'a> {
         self.config.is_debugging() || self.configuration.is_verbose()
     }
 
+    pub fn store_path(&self) -> String {
+        self.config.store_path().unwrap_or(self.configuration.store_path())
+    }
+
     pub fn get_rtp(&self) -> String {
         if let Some(rtp) = self.config.get_rtp() {
             rtp