Update gem

[ejhayes]

Thanks for this useful gem! It appears that the gem is slightly outdated with the repo--I'm using version 1.1.1 from:

https://rubygems.org/gems/ETL

It would be great to include this commit in the gem version:

6f03b66#diff-e9d748de5d81e4ffb51da4bbf7a98591

Otherwise info/debug are set to private methods.

./some-script.rb:71:in `block (2 levels) in <main>': private method `info' called for #<ETL:0x007fd9aa03d3e8> (NoMethodError)