S3: Format x-amz-date with year-of-era (akka#679)

"YYYY" in `DateTimeFormatter.ofPattern("YYYYMMdd")` means
week-based-year, which formats `LocalDate.of(2017, 12, 31)` as
"20181231" and results in unexpected rejections from S3 as below:

> The difference between the request time and the current time is
too large.

Replacing it with "yyyy" fixes the bug.

MongoDb: Sink (akka#164) and Flow

* Add mongo sink
* add mongo update and delete operations
* document mongo update and delete operations.
* Seperate sink and flow.

Don't clear between building and deploying

Hopefully fixes akka#478

links to squbs components akka#435

Elasticsearch connector (akka#221)

Elasticsearch connector (akka#221)

FTP Homogenize model (fixes akka#395) (akka#407)

Merge pull request akka#370 from 2m/wip-official-sbt-bintray-2m

Back to the official sbt-bintray plugin

Merge pull request akka#311 from 2m/wip-sqs-one-akka-version-2m

akka#310 exclude newer Akka dependency

Merge pull request akka#222 from matsluni/more_options_on_configurati…

…on_of_connectionFactory

AMQP: add more options to configuration of the ConnectionFactory, akka#191