Integrates encryption/decryption within the Cryptographer. Close #63

Includes unittests. Also reformats test_inspector to avoid using cli functions

pisa/tools.py

@@ -39,8 +39,3 @@ def in_correct_network(network):
         correct_network = True
 
     return correct_network
-
-
-def check_txid_format(txid):
-    # TODO: #12-check-txid-regexp
-    return isinstance(txid, str) and re.search(r"^[0-9A-Fa-f]{64}$", txid) is not None

pisa/watcher.py

@@ -180,7 +180,12 @@ class Watcher:
         for locator, dispute_txid in matches.items():
             for uuid in self.locator_uuid_map[locator]:
 
-                justice_rawtx = Cryptographer.decrypt(self.appointments[uuid].encrypted_blob, dispute_txid)
+                try:
+                    justice_rawtx = Cryptographer.decrypt(self.appointments[uuid].encrypted_blob, dispute_txid)
+
+                except ValueError:
+                    justice_rawtx = None
+
                 justice_tx = BlockProcessor.decode_raw_transaction(justice_rawtx)
 
                 if justice_tx is not None: