Merge pull request #60 from kale/master

Revert to 1.8.7 syntax - not officially supported since 1.8.7 has been EOL'd.
version bump for release
Improve lists.member_info example.
Add unsubscribe example to readme
Merge pull request #63 from eriktrautman/patch-1

Add unsubscribe example to readme
Merge pull request #62 from envylabs/master

Improve lists.member_info example.
Update README.markdown
Update README.markdown
Update README.markdown
allow http headers to be set to support auto-translate

In order for MailChimp to utilize auto-translate (for example sending a confirmation email in German), it requires the Accept-Language header to be sent.  Allow headers to be specified in the params
added test for passing in http headers params to api
added additional test for http headers
Merge pull request #67 from digitalmoksha/master

allow http headers to be set to support auto-translate
Add Rubinius gems, JRuby and Rubinius to .travis.yml
Merge pull request #71 from petergoldstein/feature/add_jruby_and_rbx_to_travis

Add Rubinius gems, JRuby and Rubinius to .travis.yml
Fix batch_subscribe examples.
Merge pull request #72 from santos-bt/fix_batch_subscribe_examples

Fix batch_subscribe examples.
fix grammar
add note: prefix
Simplify message in raised errors