Apply requested changes

- Adds a PRG based on a hardcoded seed to make the tests reproducible (get_random_value_hex)
- Updates all the tests replacing urandom for get_random_value_hex
- Properly places misplaced bitcoin_cli in bitcoin_sim_tests
- Typos

test/unit/conftest.py

@@ -1,4 +1,5 @@
 import pytest
+import random
 import requests
 from time import sleep
 from threading import Thread
@@ -27,6 +28,17 @@ def run_api():
     sleep(0.1)
 
 
+@pytest.fixture(scope='session', autouse=True)
+def prng_seed():
+    random.seed(0)
+
+
+def get_random_value_hex(nbytes):
+    pseudo_random_value = random.getrandbits(8*nbytes)
+    prv_hex = '{:x}'.format(pseudo_random_value)
+    return prv_hex.zfill(2*nbytes)
+
+
 def generate_block():
     requests.post(url="http://{}:{}/generate".format(HOST, PORT), timeout=5)
     sleep(0.5)