expections added.

musixmatch/expections.py

@@ -0,0 +1,16 @@
+import six
+
+
+class MusixmatchException(Exception):
+    """Musixmatch exception"""
+
+    def __init__(self, message=None, **kwargs):
+        self.message = six.text_type(message) if message else "Unknown error"
+        super(MusixmatchException, self).__init__(message, **kwargs)
+
+    def __str__(self):
+        return self.message
+
+
+class NotFound(MusixmatchException):
+    message = six.text_type("Not Found")