Multi package build for publishing

[tmbo]

Goal:
Publish project to central repository for easier usage. This avoids the need for every user to download / compile the library manually.

Changes:

• sub projects for every solver --> user can decide which solver he wants to pull into his project
• prepared project for push to sonatype

Open:

• Change in documentation. To use the libary a user needs to pull two dependencies (core and at least one solver), i.e.

libraryDependencies ++= Seq(
  "com.github.vagm" %% "optimus" % "2.0.0-SNAPSHOT",
  "com.github.vagm" %% "optimus-solver-gurobi" % "2.0.0-SNAPSHOT"
)

Please let me know if you want to merge this. If so, I'd also change the documentation accordingly. If you do not want to merge, I would need to publish the library using a different group since I need it for a different project.

[vagmcs]

Hello Tom,

Thank you for your proposal and contribution. Publishing Optimus into a repository is something I also have been thinking lately. But I have a consideration about partitioning the library into sub projects. I will think about it in the following days, review your changes and give you feedback about the pull request.

In the meantime please follow the contributing instructions (CONTRIBUTING.md) and make the pull request into the development branch (not master).

Thank you

[tmbo]

Sure, I will create a new PR against dev then.

I would say that it is quite common to split a library to reduce the number of chained dependencies.