Document 0.10 upgrade process

Definition of done

Documentation about how to upgrade soledad from 0.9.x to 0.10.x

(the migration script itself is a separate issue, tracked by soledad issue soledad#8420 (closed)).

Dicussion

Something like this? Need to test it.

cd leap_platform
git checkout release/0.10
sudo gem install leap_cli --version 1.9
cd 
leap deploy
leap run 'systemctl leap_mx stop' mx

option 1: interactive

  leap run --stream '/scripts/migration/0.8.2/migrate.py --do-migrate' soledad
    wait for it to finish (will print DONE)
    rerun if interrupted
  leap deploy

option 2: background

   leap run '/scripts/0.8.2/migrate.py --do-migrate --log-file /tmp/upgrade.log --run-in-background' soledad
   leap run --stream 'tail -f /tmp/upgrade.log' soledad
     wait for it to finish (will print DONE)
     to restart, run 
       leap run 'pkill -TERM -f migrate.py' soledad
     and try again.
   leap deploy

https://0xacab.org/leap/soledad/blob/develop/scripts/migration/0.8.2/README.md

(from redmine: created on 2016-08-30)