Updates teos to work with the new conf file format and redefines how objects are built

Configuration parameters are now load from a .conf file (see template.conf as an example).

The code has 3 config levels: default (teos/__init__.py), config file (<data_dir>/teos.conf) and command line.
Most of the config parameters are only modificable trough the config file for now.
The priority order is: command line, config file, default.

Objects that need config parameters are now built in teosd instead of inside other classes. Therefore teosd acts like a factory and config parameters don't have to be passed around between objects. This also implies that a lot of the object creation logic has been changed.

This should simplify unit testing.

teos/tools.py

@@ -1,7 +1,6 @@
-from http.client import HTTPException
 from socket import timeout
+from http.client import HTTPException
 
-import teos.conf as conf
 from teos.utils.auth_proxy import AuthServiceProxy, JSONRPCException
 
 """
@@ -10,25 +9,38 @@ Tools is a module with general methods that can used by different entities in th
 
 
 # NOTCOVERED
-def bitcoin_cli():
+def bitcoin_cli(btc_connect_params):
     """
     An ``http`` connection with ``bitcoind`` using the ``json-rpc`` interface.
 
+    Args:
+        btc_connect_params (:obj:`dict`): a dictionary with the parameters to connect to bitcoind
+            (rpc user, rpc passwd, host and port)
+
     Returns:
         :obj:`AuthServiceProxy <teos.utils.auth_proxy.AuthServiceProxy>`: An authenticated service proxy to ``bitcoind``
         that can be used to send ``json-rpc`` commands.
     """
 
     return AuthServiceProxy(
-        "http://%s:%s@%s:%d" % (conf.BTC_RPC_USER, conf.BTC_RPC_PASSWD, conf.BTC_RPC_HOST, conf.BTC_RPC_PORT)
+        "http://%s:%s@%s:%d"
+        % (
+            btc_connect_params.get("BTC_RPC_USER"),
+            btc_connect_params.get("BTC_RPC_PASSWD"),
+            btc_connect_params.get("BTC_RPC_CONNECT"),
+            btc_connect_params.get("BTC_RPC_PORT"),
+        )
     )
 
 
 # NOTCOVERED
-def can_connect_to_bitcoind():
+def can_connect_to_bitcoind(btc_connect_params):
     """
     Checks if the tower has connection to ``bitcoind``.
 
+    Args:
+        btc_connect_params (:obj:`dict`): a dictionary with the parameters to connect to bitcoind
+            (rpc user, rpc passwd, host and port)
     Returns:
         :obj:`bool`: ``True`` if the connection can be established. ``False`` otherwise.
     """
@@ -36,18 +48,23 @@ def can_connect_to_bitcoind():
     can_connect = True
 
     try:
-        bitcoin_cli().help()
+        bitcoin_cli(btc_connect_params).help()
     except (timeout, ConnectionRefusedError, JSONRPCException, HTTPException, OSError):
         can_connect = False
 
     return can_connect
 
 
-def in_correct_network(network):
+def in_correct_network(btc_connect_params, network):
     """
     Checks if ``bitcoind`` and the tower are configured to run in the same network (``mainnet``, ``testnet`` or
     ``regtest``)
 
+    Args:
+        btc_connect_params (:obj:`dict`): a dictionary with the parameters to connect to bitcoind
+            (rpc user, rpc passwd, host and port)
+        network (:obj:`str`): the network the tower is connected to.
+
     Returns:
         :obj:`bool`: ``True`` if the network configuration matches. ``False`` otherwise.
     """
@@ -56,7 +73,7 @@ def in_correct_network(network):
     testnet3_genesis_block_hash = "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"
     correct_network = False
 
-    genesis_block_hash = bitcoin_cli().getblockhash(0)
+    genesis_block_hash = bitcoin_cli(btc_connect_params).getblockhash(0)
 
     if network == "mainnet" and genesis_block_hash == mainnet_genesis_block_hash:
         correct_network = True