input: Write a python function to create a Circle class with methods to compute the area and the circumference of a circle.
  assert Circle(5).area() == 78.5
  assert Circle(5).circumference() == 31.400000000000002
  assert Circle(3).area() == 28.26
  assert Circle(3).circumference() == 18.84
output: import math
  
  class Circle:
      def __init__(self, radius):
          self.radius = radius
  
      def area(self):
          return round(math.pi * (self.radius ** 2), 2)
  
      def circumference(self):
          return round(2 * math.pi * self.radius, 2)