Rollback chromedriver version used in Docker to 2.38
Rollback chromedriver version used in Docker to 2.38

Our Docker image uses Chromium v57, which is not supported by
chromedriver versions after 2.38. See
https://bugs.chromium.org/p/chromedriver/issues/detail?id=2445

The reason that the version of chromium is so old is that our base
image ruby:2.3.6 (the standard image for Ruby 2.3.6 on DockerHub) is
built on Debian 8 (jessie), which was made obsolete over a year ago.

The best solution is probably to upgrade the application to Ruby 2.3.7
(if not later), so we can use the official ruby:2.3.7 image, which is
kept up-to-date (it has Chromium 68).

Alternatively, we could try to install Chromium from a more up-to-date
repository, but this is probably not worth the trouble.

AyuntamientoPuertoReal/decidePuertoReal,consul/consul,usabi/consul_san_borondon,AyuntamientoMadrid/participacion,AyuntamientoMadrid/participacion,AyuntamientoMadrid/participacion,AjuntamentdeCastello/consul,AjuntamentdeCastello/consul,usabi/consul_san_borondon,CDJ11/CDJ,consul/consul,CDJ11/CDJ,usabi/consul_san_borondon,consul/consul,AjuntamentdeCastello/consul,CDJ11/CDJ,AyuntamientoMadrid/participacion,CDJ11/CDJ,usabi/consul_san_borondon,AyuntamientoPuertoReal/decidePuertoReal,AjuntamentdeCastello/consul,consul/consul,consul/consul,AyuntamientoPuertoReal/decidePuertoReal