Revert "update send_nivo_text as send_synth_text"

This reverts commit 5ba3e1422770ae53ffdeabc6c34f1b9edc0be367.
Revert "update text bulletin url (to correct when text bulletin will be reactived)"

This reverts commit 06dd7eb5b8833b0432ccf6f790cf662313af0422.
Add a base class for bots.
Use only one store for all bulletin types.
Start SLF Bot