Add method to check if a table exists in cartoDB

Previously, we would call for cartoDB table deletion even if it didn't exist, thus
getting useless warnings.

:pear: leon
Bump version :pear: leon
Merge branch 'master' of git.realestate.com.au:data-distribution/cartodb-dashboard-python

* 'master' of git.realestate.com.au:data-distribution/cartodb-dashboard-python:
  Bump version :pear: leon
  Add method to check if a table exists in cartoDB

Conflicts:
	setup.py