Timescaledb: 0.0.10-beta Release

High-level changes * New time_bucket functions for doing roll-ups on varied intervals * Change default partition function (thanks @robin900) * Variety of bug fixes

Notable commits * [1c4868d] Add documentation for chunk_time_interval argument * [55fd2f2] Fixes command tag return for INSERTs on hypertables. * [c3f930f] Add time_bucket functions * [b128ac2] Fix bug with INSERT INTO...SELECT * [e20edf8] Add better error checking for index creation. * [72f754a] use PostgreSQL's own hash_any function as default partfunc (thanks @robin900) * [39f4c0f] Remove sample data instructions and point to docs site * [9015314] Revised the get_general_index_definition function to handle cases where indexes have definitions other than just CREATE INDEX (thanks @bricklen)