Update app to Rails 5.x

[gsrohde]

• Rails 3.2 is no longer supported; current version is 5.1
  • Github identifies this as 'moderate' security risk; many gems also need to be updated

Please outline steps required to update BETYdb to Rails 5.x, starting with the bare minimum required as well as nice to have features, alongside estimates of time / effort required.

[max-zilla]

@gsrohde reports currently on 4.1

[dlebauer]

@gsrohde and @robkooper should there be a release at 4.1 to make sure it works in the wild?

[robkooper]

yes please, this way we can check it out

[craig-willis]

Created separate issue for 4.1 upgrade https://github.com/PecanProject/bety/issues/566

[max-zilla]

5.1 deployed for testing. on pecan-dev.

[max-zilla]

@robkooper wants to look at dockerfile. @dlebauer have you reviewed?

[max-zilla]

Updating various sites as part of a rollout for this will be more involved than usual.

@gsrohde can you write clear requirements for this process? Ruby version/installation, OS, going from previous rails 4 app to rails 5 app w/ prerequisites.

[max-zilla]

mostly done. just need PR.

[max-zilla]

@robkooper needs to review documentation and we can close.