Include only production runtime dependencies in the docker image - ex…

…cluding spring dev-tools (#16)

added few tiny fixed to the openapi generator plugin configuration

- fixed validation issues
- don't generate models for aliases
- ensure that all input specs are relative to the project root

fix spotless year license header

Add throws Exception to controller methods in order to allow handling…

… checked exception in general exception handler (#13)

do not generate timestamps and comments - we generate those files on …

…every build.

use project name as docker image name (#11)

* use project name as docker image name

* fix type and use project.name.toLowerCase

* remove redundant global var

Refactoring of spring plugin

**What is this about?**

Split the plugin in 2:
- core spring
- spring db

Reason: adapters will not have DB support

What else:
* removed version properties - Spring manages them through their BOM
* updated documentation
* removed swagger-ui as dependency
* use findProperty() instead of ext.properties[]
* added skipLicenseHeader property to disable java header in the formatter

Some concerns: The Spring managed versions are slightly older than ours. However, they choose those versions for reason - they should be tested for compatibility
* postgresql.version, 42.3.7 -> 42.5.0
* liquibase.version, 4.9.1 -> 4.17.0

added maven repo configuration

Merge pull request #2 from clippings/initial-import

initial commit