Dockerfile does not build with previous releases

[GustavGroenborg]

When trying to build an earlier release of the example-crud project, an error will occur upon trying to build the project with CMake. This error occurs, because the downloaded dependencies, does not match that of the required dependencies.

To prevent this issue from arising, the Dockerfile should support the possibility of specifying a version to be downloaded.

[GustavGroenborg]

I have solved this issue by implementing a fix in PR #37.