Slow startup time of cherami-server-standalone Docker image

[HelloGrayson]

YARPC for Go is now using the Cherami server to run end-to-end tests, which is awesome, except that it adds minutes to our test suite completion time because this image takes so long to become ready.

Guessing this is related to provisioning Cassandra w/ schema and required data. Let's get that way down to at least >10s. Here are some ideas:

• Create and maintain a Cassandra image that has the schema already provided
• Mount the dir Cassandra persists to, and then use Travis CI's cache feature to ensure subsequent runs are speedy.

Anything would be useful on our end, this makes things really slow.

[datoug]

ack