Major upgrade and cleanup

[spauny]

Did a major cleanup of the plugin and added support for sequential deployment with delay when the server has multiple nodes, among other improvements.
Feel free to review, QA and merge if you want to.

[vovkozt]

Hello, Iulian

I'm done code review of your changes. Please see summary below:

The following functionality is missing

• authorization by login/password
• artifact registration in Deployment Manager in Jelastic dashboard
• proxy settings usage for network

The following functionality doesn't work properly

• 'password' parameter is used as 'apiToken'
• 'api_hoster' is renamed to 'apiHost' (needs to leave old variable also to support backward compatibility)
• http requests are used while we use https
• last changes (from JE-51840 Add deploy optional parameters) are not included (no need for separate 'delay' parameter)
• 'isSequential' parameter is redundant and it is not using directly by deploy service method (sequential deployment apply if is 'delay' parameter sets to any positive value)

We would also suggest to fix the following:

• our policy is to use our public client lib instead of custom one (I mean com.lindar:well-rested-client), we have plans to exclude apache http client from plugin also
• we do not use lombok for our projects