Support SSL option for Presto connector

[toru-takahashi]

Hello,

First of all, Thank you for supporting Presto adopter. I'm happy it because I gave up it when dmemo was released.
I have a question, so I file this issue. If you have a chance, please give me your advice.

Description

I tried our Presto environment (TreasureData), which requires SSL parameter with 443 port, to connect from dmemo.
But, I noticed that connection_config doesn't have SSL option. Then, ssl: false is always used as default in presto client library. I would like to add a new parameter to allow users to specify ssl parameter.
For example,

    def connection_config
      {
        catalog: @data_source.dbname,
        server: "#{@data_source.host}:#{@data_source.port}",
        user: @data_source.user,
        password: @data_source.password.presence,
        ssl: {verify: false},
      }.compact
    end

Question

I'm working on making a PR to support ssl option.
But, I noticed that an existing Presto user needs to migrate tables in order to add ssl option if I follow bigquery adaptor implementation. (Ex. I saw data_sources.schema and bigquery_configs.schema)

I want to minimize the code change without any table migration.

Thus, I would like to know whether the following change is acceptable for your team?

• Host parameter allows URL like https://xxxxx/?ssl_verify=false instead of only xxxxx.
• Then, presto_adaptor.rb parses it and build a new connection_config.

If this is acceptable, I'll try to make a PR for this.
If this is not acceptable, I'll follow a way as same as bigquery adaptor.

I'm not familiar with Rails. So, if you have any advise, that would be helpful.

Thank you,