Fans of The Wire will appreciate this one. 
For those that haven't seen the show, the Barksdale Organization has a simple method for encoding telephone numbers exchanged via pagers: "Jump to the other side of the 5 on the keypad, and swap 5's and 0's."
Here's a keypad for visualization.
```
┌───┬───┬───┐
│ 1 │ 2 │ 3 │
├───┼───┼───┤
│ 4 │ 5 │ 6 │
├───┼───┼───┤
│ 7 │ 8 │ 9 │
└───┼───┼───┘
    │ 0 │
    └───┘
```
Detective, we're hot on their trail! We have a big pile of encoded messages here to use as evidence, but it would take way too long to decode by hand. Could you write a program to do this for us?
Write a funciton called decode(). Given an encoded string, return the actual phone number in string form. Don't worry about input validation, parenthesies, or hyphens.
def decode(string):
    cipher = {'1':'9','2':'8','3':'7','4':'6','5':'0','6':'4','7':'3','8':'2','9':'1','0':'5'}
    return ''.join([cipher[x] for x in string])

def decode(string):
    cipher = {'1':'9','2':'8','3':'7','4':'6','5':'0','6':'4','7':'3','8':'2','9':'1','0':'5'}
    return ''.join([cipher[x] for x in string])
