Moving tests to /tests and removing /doc folder. Docs are now in seperate repository

tests/test-link-preview.md

@@ -0,0 +1,23 @@
+# Link Preview Tests
+
+Link previews should embed previews of the contents of a hyperlink from a message or comment in the center channel directly below the message or comment.
+
+Post location variation: 
+
+1. Post as message in center channel with RHS closed (link preview should render under message) 
+2. Post as message in center channel with RHS open (link preview should render under message) 
+3. Post as comment in RHS (link preview should not render) 
+4. View comment in center channel with RHS closed (link preview should render under message) 
+5. View comment in center channel with RHS open (link preview should render under message) 
+6. Search for post in RHS with link
+
+Post the following links one per message in the above variations: 
+
+Twitter Link Preview: 
+https://twitter.com/mattermosthq/status/664928489078820865
+
+Vine: 
+https://vine.co/v/eDeVgbFrt9L
+
+Wikipedia
+https://en.wikipedia.org/wiki/Princess_Bubblegum