Merge pull request #4 from edx/feanil/python-modernize

Run python-modernize to update this repo for python 3.

Update README.md

Add the exploration version to the data payload of each analytics event.

Change tracker.emit to self.runtime.publish, per Sarina's advice.

Merge branch 'master' of https://github.com/oppia/xblock

Add a field in Studio for the component's display name.

Update README.md

Add display_name field and author_view method; remove width/height fields; add event tracking; include a local copy of the embedding script with an appropriate title for the iframe.

Clarify the README further.

Update README file.

Add the actual XBlock.

Initial commit