Upgrade to Spring 3

[mslowiak]

Closes: #43

[mslowiak]

@josdem working on my side but please test it on your side as well because it is big change

[mslowiak]

I found out problems with tests, changing to draft

[josdem]

Hi @mslowiak, thanks for creating a PR to update to spring 3.0.5 this is the error I am seeing when running tests or trying to start the application:

Caused by: java.lang.ClassNotFoundException: javax.servlet.http.HttpServletRequest
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:467)

Not sure why this is happening. I will investigate this in detail

[mslowiak]

I think that the springfox is the problem here - it is not yet compatible with Spring 3.
springfox/springfox#3983

If we want to move to the Spring 3, then we should migrate springfox to springdoc, see migration guide

[josdem]

I agree; springfox is the issue here. We want to migrate to Spring Doc as the next step. I went ahead and create a new issue in the repository, please take a look at it here