Add a save function to save a call in database

app.py

@@ -55,7 +55,7 @@ class Call(json.JSONEncoder):
 
     @classmethod
     def load(cls, callid, db):
-        results = db.execute('SELECT caller, callee, owner, callid, history, state FROM calls WHERE callid = ?;', (callid,))
+        results = db.execute('SELECT caller, callee, owner, callid, history FROM calls WHERE callid = ?;', (callid,))
         try:
             result = results.fetchone()
             object = cls(result[0], result[1], result[2])
@@ -65,6 +65,14 @@ class Call(json.JSONEncoder):
         except:
             return None
 
+    def save(self, db):
+        '''
+        Save the Call to database.
+        '''
+        db.execute('''INSERT OR REPLACE INTO calls (caller, callee, owner, callid, history)
+                VALUES (?, ?, ?, ?, ?)
+        ''', (self.caller, self.callee, self.owner, self.callid, json.dumps(self.history)))
+
 # We need a decorator to check if our query is authenticated.
 # We will store an API key and SECRET in ur database, the client
 # needs to have both of them.