FEAT: Add flake8 (#267)

* init flake8

* exclude nostr client, and add ds_store to gitignore

* fix flake8 F811 issue, redefinition of unused variables

* add flake8 to workflow

* F401 unused imports

* F541 f-string is missing placeholders

* E501 line too long > 150 characters

* E722 no bare except

* E402 module level import not at top of file

* F405 no star imports

* E712 comparison to False should be 'if cond is False:'

* F841 local variable is assigned to but never used

* E266 too many leading '#' for block comment

* E265, E261

* E713 test for membership should be 'not in'

* E711, E741

E741 ambiguous variable name 'l'
E711 comparison to None should be 'if cond is None:'

* flake config

* isort

* refactor makefile flake8 usage

* reflaking the rebase

* black

* fix tests?

* black

* fix line lenght it test_cli

* sort out makefile

* fix strings

* reintroduce black-check

* reflake and mypy

* isort

* Update cashu/wallet/wallet.py

Co-authored-by: Angus Pearson <angus@toaster.cc>

* Update cashu/mint/ledger.py

Co-authored-by: Angus Pearson <angus@toaster.cc>

---------

Co-authored-by: Angus Pearson <angus@toaster.cc>

cashu/core/script.py

@@ -2,13 +2,8 @@ import base64
 import hashlib
 import random
 
-COIN = 100_000_000
-TXID = "bff785da9f8169f49be92fa95e31f0890c385bfb1bd24d6b94d7900057c617ae"
-SEED = b"__not__used"
-
 from bitcoin.core import CMutableTxIn, CMutableTxOut, COutPoint, CTransaction, lx
-from bitcoin.core.script import *
-from bitcoin.core.script import CScript
+from bitcoin.core.script import OP_CHECKSIG, SIGHASH_ALL, CScript, SignatureHash
 from bitcoin.core.scripteval import (
     SCRIPT_VERIFY_P2SH,
     EvalScriptError,
@@ -17,6 +12,10 @@ from bitcoin.core.scripteval import (
 )
 from bitcoin.wallet import CBitcoinSecret, P2SHBitcoinAddress
 
+COIN = 100_000_000
+TXID = "bff785da9f8169f49be92fa95e31f0890c385bfb1bd24d6b94d7900057c617ae"
+SEED = b"__not__used"
+
 
 def step0_carol_privkey():
     """Private key"""