[travis] - add actionmailer

[ahorek]

add action mailer job #1300

[ahorek]

@jeremy do you have an idea how to fix? could you try to upgrade rvm and gpg keys manually?

https://travis-ci.org/mikel/mail/jobs/470182472

rvm get master
Downloading https://get.rvm.io
Downloading https://raw.githubusercontent.com/rvm/rvm/master/binscripts/rvm-installer.asc
Verifying /home/travis/.rvm/archives/rvm-installer.asc
gpg: Signature made Wed 12 Dec 2018 04:06:03 PM UTC using RSA key ID 39499BDB
gpg: Can't check signature: No public key
Warning, RVM 1.26.0 introduces signed releases and automated check of signatures when GPG software found. Assuming you trust Michal Papis import the mpapis public key (downloading the signatures).
GPG signature verification failed for '/home/travis/.rvm/archives/rvm-installer' - 'https://raw.githubusercontent.com/rvm/rvm/master/binscripts/rvm-installer.asc'! Try to install GPG v2 and then fetch the public key:
    gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
or if it fails:
    command curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
the key can be compared with:
    https://rvm.io/mpapis.asc
    https://keybase.io/mpapis
NOTE: GPG version 2.1.17 have a bug which cause failures during fetching keys from remote server. Please downgrade or upgrade to newer version (if available) or use the second method described above.
/home/travis/.rvm/scripts/functions/cli: line 243: return: _ret: numeric argument required

[jeremy]

Let's leave rbx as-is and add truffleruby in a separate PR. This PR can focus on integration testing with Action Mailer alone.

[ahorek]

ok

[jeremy]

bundle update --source mail may be sufficient, rather than removing the lock and reinstalling

[jeremy]

Second bundle install is superfluous. Can remove it.

[jeremy]

Great!