I'm not sure exactly what changed here (did we change the `$VERBOSE`
setting?), but I'm not seeing a whole lot of warnings when running the
test suites locally and in CI. For example:
```
Started
........................................./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
............../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
......../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
.../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
........./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
...
..../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
....../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
..../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
......./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
........./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
........../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
................./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
.../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
..../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
....../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
..........
........./home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
....../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
......../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
......../home/travis/build/stripe/stripe-ruby/lib/stripe/api_operations/list.rb:6: warning: instance variable @opts not initialized
............./home/travis/build/stripe/stripe-ruby/lib/stripe/stripe_object.rb:35: warning: instance variable @values not initialized
./home/travis/build/stripe/stripe-ruby/lib/stripe/stripe_object.rb:35: warning: instance variable @values not initialized
...................../home/travis/build/stripe/stripe-ruby/lib/stripe/transfer.rb:8: warning: instance variable @api_key not initialized
..............
..
Finished in 0.785621037 seconds.
```
Most of these are due to unused or uninitialized variables. This patch
fixes all warnings by fixing offending code.
Usage on a top-level collection:
```
Stripe::Customer.list.auto_paging_each do |customer|
puts customer
end
```
Usage on a subcollection:
``` ruby
customer.invoices.auto_paging_each do |invoice|
puts invoice
end
```
We've also renamed `#all` to `#list` to prevent confusion ("all" implies
that all resources are being returned, and in Stripe's paginated API
this was not the case). An alias has been provided for backward API
compatibility.
Fixes#167.
Replaces #211 and #248.
