able to create non-existing keyspace

[shenghu]

Description

I'm looking at using cassandra as our database and build app using loopback. Current loopback-connector-cassandra can not create keyspace if it doesn't exist. It might be the design that it is expected to create keysapce instead of letting app to create it itself. But it will be more convenient if loopback-connector-cassandra has the capability.

So I add the following setting to DataSource setting

• createKeyspace: true to create keyspace. Otherwise do not like it is today
• replication: object to define replication setting. e.g.

          replication: {
            class: 'NetworkTopologyStrategy', 
            dc1: 1,
          }

Please review the PR to see if it can be merged. Any change needed please let me know.

So I fixed the failure test about tuple by adding support of Tuple.

Related issues

• connect to https://github.com/strongloop/loopback-connector-cassandra/issues/24
• connect to https://github.com/strongloop/loopback-connector-cassandra/issues/10

Checklist

• [x] New tests added or existing tests modified to cover all changes
• [x] Code conforms with the style guide

[shenghu]

@Setogit @kjdelisle can you please review this PR? Thanks. I hope to use the updated version in my project asap.

[shenghu]

The last code added support of nested tuple.

[jannyHou]

@slnode test please

[dhmlau]

@jannyHou , wanna double check.. it's good to merge? After merging, I can release it. Thanks.

[jannyHou]

@shenghu PR landed 🚢 Thank you again for all the effort of adding this important feature in the cassandra connector!

@dhmlau merged :) hope it also fixes the juggler's CI!

[dhmlau]

Published as 1.5.0.