Remove many unwrap

src/dictionary_test.rs

@@ -171,11 +171,17 @@ impl DictionaryQuizState {
         self.is_help = false;
         self.answer = String::new();
 
-        if self.current_set.is_empty() {
-            self.update_set();
-        }
+        let next : WordData =
+        match self.current_set.pop() {
+            Some(word) => {
+                word
+            }
+            None => {
+                self.update_set();
+                 self.current_set.pop().expect("Empty set")
+            }
+        };
 
-        let next = self.current_set.pop().unwrap();
         if self.reverse {
             self.view = next.value.clone();
             self.correct = next.key.clone();