Modified answer method to keep track of the correct answer on the variable...

Modified answer method to keep track of the correct answer on the variable score, and changed score intitial numeric property value from 100 to 0.

main.py

@@ -72,7 +72,7 @@ class QuizzerApp(App):
     paused = BooleanProperty(False)
     correct = BooleanProperty(False)
 
-    score = NumericProperty(100)
+    score = NumericProperty(0)
 
     def build(self):
         inspector.create_inspector(Window, self)
@@ -95,6 +95,8 @@ class QuizzerApp(App):
         question = self.questions[-1] if len(self.questions) > 0 else self.DEFAULT_QUESTION
         self.paused = True
         self.correct = answer == question[2]
+        if self.correct:
+            self.score += 1
         Clock.schedule_once(lambda delta: self.unpause(), PAUSE_TIME)
 
     def unpause(self):