correct bug in sidekiq client middleware with sidekiq >= 2.12.1

See issue https://github.com/influitive/apartment/issues/59 for more
details
upgrade jruby for travis
new files for new rvm
added TODO with things... to... do
more todos
add HostHash elevator

allows to switch database based on full host and using
a hash to find corresponding database name
escape dot in domain regex to match www.
add param to specify on which db to apply rake task
add rake task to create databases
revert apartment:seed task dependency to db:seed
Tests for #60