Using tar for incremental backups

[jrbalderrama]

Instead of ansible module use tar for incremental backups of influxdb

[msimonin]

We need to evaluate the benefit before. I don't know how the incremental option will perform with the way influxdb is storing its internal datas.

One idea would be to

• take the data from an experimental test case.
• untar everything
• take the first backup dir and tar again the influxdb data in incremental mode
• do the same for subsequent influxdb data dir

check if we gain anything in term of archiving time and space.