feat(ects): add some helper functions for etcs

src/ects.py

@@ -2,6 +2,7 @@ import pygame
 
 from src.settings import START_ECTS_VALUE, ECTS_UPDATE_INTERVAL
 
+
 class ECTS:
     def __init__(self):
         # total amount of ECTS the player has at the beginning
@@ -24,3 +25,9 @@ class ECTS:
     # beer increases amount of how much ECTS are earned per second
     def upgrade_rate(self, extra_ects):
         self.ects_per_second += extra_ects
+
+    def is_over_balance(self, amount):
+        return self.ects_balance >= amount
+
+    def decrease_balance(self, amount):
+        self.ects_balance -= amount