Improve posting trades to OANDA and make everything more robust

core/exchanges/__init__.py

@@ -164,6 +164,18 @@ class BaseExchange(object):
     def get_account(self):
         raise NotImplementedError
 
+    def extract_instrument(self, instruments, instrument):
+        for x in instruments["itemlist"]:
+            if x["name"] == instrument:
+                return x
+        return None
+
+    def get_currencies(self, symbols):
+        raise NotImplementedError
+
+    def get_instruments(self):
+        raise NotImplementedError
+
     def get_supported_assets(self):
         raise NotImplementedError