The new gem!!!

## Core Features
- [x] Authentication: Will use OAuth by default. The user will only need to do an setup process to get his client_passphrase.
- [x] OAuth timeout management
- [x] Setup scripts: Rails + Non Rails (RAILS for now)
- [x] Executable. I've added an executable so that the users can play with the gem directly from there console. 
- [ ] Errors Management
- [ ] Pagination
 
## Resources
- [x] Users: CREATE, UPDATE, FETCH
- [x] Wallets: CREATE, UPDATE, FETCH
- [x] Payins: CREATE (WebCard), FETCH
- [x] Payouts: CREATE (BankWire), FETCH
- [x] Transfers: CREATE, FETCH
- [x] Transactions: CREATE, FETCH
- [x] Bank Details: CREATE, FETCH

## Tests
**All of those will need to be updated to test the errors management methods**
- [x] Clients
- [x] Users 
- [x] Wallets
- [x] Payins
- [x] Payouts
- [x] Transfers
- [x] Transactions <- Will need further tests after payin, payout and filters are implemented.
- [x] Bank Details