add check script

[alexcos20]

Closing #139

Changes proposed in this PR:

• add check script

Sample output:

python3 scripts/check_testnet.py 288 
Number of Predictoor contracts: 12 - OK
------------------------------------------------------------
Predictions:
ADA/USDT: 288/288 - OK
BNB/USDT: 190/288 - FAIL
TRX/USDT: 190/288 - FAIL
SOL/USDT: 287/288 - OK
ETH/USDT: 288/288 - OK
DOGE/USDT: 287/288 - OK
XRP/USDT: 190/288 - FAIL
ETH/USDT: 0/288 - FAIL
BTC/TUSD: 284/288 - OK
DOT/USDT: 188/288 - FAIL
LTC/USDT: 188/288 - FAIL
BTC/USDT: 285/288 - OK

True Values:
ADA/USDT: 287/288 - OK
BNB/USDT: 287/288 - OK
TRX/USDT: 287/288 - OK
SOL/USDT: 287/288 - OK
ETH/USDT: 287/288 - OK
DOGE/USDT: 287/288 - OK
XRP/USDT: 287/288 - OK
ETH/USDT: 0/288 - FAIL
BTC/TUSD: 287/288 - OK
DOT/USDT: 287/288 - OK
LTC/USDT: 287/288 - OK
BTC/USDT: 287/288 - OK

Checking account balances
---------- predictoor1's Wallet ----------
Address: 0xE02A421dFc549336d47eFEE85699Bd0A3Da7D6FF
OCEAN Balance: 712.64
Native Balance: 152.57

---------- predictoor2's Wallet ----------
Address: 0x00C4C993e7B0976d63E7c92D874346C3D0A05C1e
OCEAN Balance: 1019.48
Native Balance: 199.29

---------- predictoor3's Wallet ----------
Address: 0x005C414442a892077BD2c1d62B1dE2Fc127E5b9B
OCEAN Balance: 999.85
Native Balance: 7.17
WARNING: Low Native balance!

---------- trueval's Wallet ----------
Address: 0x005FD44e007866508f62b04ce9f43dd1d36D0c0c
OCEAN Balance: 2334.67
Native Balance: 2287.94

---------- websocket's Wallet ----------
Address: 0x008d4866C4071AC9d74D6359604762C7B581D390
OCEAN Balance: 1994.00
Native Balance: 209.19

TO DO:

• by default, we are using the last 288 epochs. it would be nice to have this value as argument, for quick tests