Create Phone number encoder.py

4445555966667###00#### -> 456600
Merge pull request #2 from fVrDev/Excersice-ATS-phone-number-encoder

Excersice: phone number encoder.
If the character in the string 1 times - he hindrance, another use them ones. Symbol '#' - repeate last symbol.
4445555966667###00#### -> 456600