Add MariaDB preset

Implement Kafka Preset

This commit also adds an ability to use pre-configured port number on
the host

Add Memcached preset

* Add Memcached preset

* Change Redis to Memcached in comments

* Add storing number as a string

* Add Memcached to registry.go for use by gnomockd

* Add tests for gnomock

* Add swagger spec for Memcached

* Add Memcached to README

* Add python sdk test for Memcached

* Add Values and ByteValues

Make string and byte slice maps separate so both can be used.

* Make preset test more readable

Make preset test a bit more readable by changing variable names

* Open only one connection in initf

* Update swagger specification

Update swagger specification for use with both ByteValues and Values.
Also specify property type of ByteValues to be a string with byte format
(base64 encoded bytes).

* Upgrade python SDK to 1.4.2

Allow using a specific container name

Add latest supported preset version to readme

Update readme

Add troubleshooting section and update example

Move all packages back go use gnomock root

Align preset versions to v0.6.0

Use latest preset versions