Merge pull request #12 from x0id/prerequisites_hook

Add data load hook

Improve the performances of reads

Add `info/1` function to retrieve table stats

Add `merger` option

[DEGA-1336] Remove unnecessary duplication of input data during loading

Add versioned functions

Add publish/subscribe mechanism

remove long log and add a supervisor

Releasing a subscriber for bert file update.

Bump version to 0.1.4