Adding history class

e Please enter the commit message for your changes. Lines starting
here is the history class

shadowtube/history.py

@@ -0,0 +1,18 @@
+class History: #Abstract class
+    def __init__(self, filename):
+        self.history = list() 
+        
+    def __size__(self):
+        return len(history)
+        
+    def parse_history(self, filename):
+        return history
+
+    def is_this_type(self, filename): # bool function, 
+        return false                  # returns false if Youtube history
+
+    def get_video(self, index):
+        return history[index]
+
+    def __iter__(self):
+        return iter(history)