XML Currency Parser

Goals

1. UI screens with new UIViewPropertyAnimator (allows user to control animation).
2. Currency converter
3. Currency rates updated every 30 seconds with Timer
4. Displaying active exchange rate
5. Ability to set amount to buy and amount to sell

Functions

1. Download XML data
2. Parse XML data into Object Structure
3. Give current rate for provided currency type
4. Display user balance for provided currency type
5. Update user balance in persistent way
6. Separate configuration file for setting URL

Unit Tests

1. Test currency list, all property should return correct count of currencies.
2. Test network API
3. Test currency converter