I encounterd what seems to be the same problem with dpl 1.10.10:
ERROR: Error installing dpl-releases:
The last version of public_suffix (>= 2.0.2, < 4.0) to support your Ruby & RubyGems was 3.0.3. Try installing it with `gem install public_suffix -v 3.0.3` and then running the current command again
public_suffix requires Ruby version >= 2.3. The current ruby version is 2.2.0.
Successfully installed multipart-post-2.1.1
Successfully installed faraday-0.15.4
/home/travis/.rvm/rubies/ruby-2.2.5/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- dpl/provider/releases (LoadError)
from /home/travis/.rvm/rubies/ruby-2.2.5/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/provider.rb:93:in `rescue in block in new'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/provider.rb:68:in `block in new'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/cli.rb:41:in `fold'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/provider.rb:67:in `new'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/cli.rb:31:in `run'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/lib/dpl/cli.rb:7:in `run'
from /home/travis/.rvm/gems/ruby-2.2.5/gems/dpl-1.10.10/bin/dpl:5:in `<top (required)>'
from /home/travis/.rvm/gems/ruby-2.2.5/bin/dpl:23:in `load'
from /home/travis/.rvm/gems/ruby-2.2.5/bin/dpl:23:in `<main>'
travis_fold:end:dpl.1
failed to deploy