Add Bitcoin symbol

Bitcoin Unicode symbol ₿ released with version 10.0

Author: Jack

forex_python/raw_data/currencies.json

@@ -20,6 +20,7 @@
   {"cc":"BOB","symbol":"Bs.","name":"Bolivian boliviano"},
   {"cc":"BRL","symbol":"R$","name":"Brazilian real"},
   {"cc":"BSD","symbol":"B$","name":"Bahamian dollar"},
+  {"cc":"BTC","symbol":"₿","name":"Bitcoin"},
   {"cc":"BTN","symbol":"Nu.","name":"Bhutanese ngultrum"},
   {"cc":"BWP","symbol":"P","name":"Botswana pula"},
   {"cc":"BYR","symbol":"Br","name":"Belarusian ruble"},
@@ -155,4 +156,4 @@
   {"cc":"ZAR","symbol":"R","name":"South African rand"},
   {"cc":"ZMK","symbol":"ZK","name":"Zambian kwacha"},
   {"cc":"ZWR","symbol":"Z$","name":"Zimbabwean dollar"}
-]
+]