Update README.md
Merge pull request #126 from vfilanovsky/master

Accommodate new EC2 Reserved Instance Model - fixes #125
add new AWS location in Frankfurt Germany eu_central_1
Merge pull request #124 from jeffreyjackson/patch-1

Update README.md
Merge pull request #127 from oli99sc/master

add new AWS location in Frankfurt Germany eu-central-1
Merge pull request #129 from vfilanovsky/master

All/Partial/No Upfront payment types refer to Heavy utilization. Medium/Light reservations are no longer available.
Merge pull request #130 from vfilanovsky/master

Add support for eu-central-1 region. Fixes #128
Merge pull request #1 from Netflix/master

Sync with Netflix