added gumlet provider (iamcal#696)

* added gumlet provider

* updated examples

* schemes updated

Author: adityapatadia

providers/gumlet.yml

@@ -0,0 +1,13 @@
+---
+- provider_name: Gumlet
+  provider_url: https://www.gumlet.com/
+  endpoints:
+  - schemes:
+    - https://www.gumlet.com/watch/*
+    - https://play.gumlet.io/embed/*
+    url: https://api.gumlet.com/v1/oembed
+    discovery: true
+    example_urls:
+    - https://api.gumlet.com/v1/oembed?url=https://www.gumlet.com/watch/6221db301c8b821b0519fba0&format=json
+    - https://api.gumlet.com/v1/oembed?url=https://www.gumlet.com/watch/6221db301c8b821b0519fba0&format=xml
+...