Fix for tar creation missing dockerfile and wrong folder name

[transamericamoon]

Currently plugin fails (does not copy dockerfile and uses folder named "tar" instead of "maven") during build when using inline assembly:

                <build>
                    <assembly>
                      <tarLongFileMode>posix</tarLongFileMode>
                      <mode>tar</mode>
                      <inline>
                        <fileSets>
                          <fileSet>
                            <directory>/Users/transamericamoon/project/dist</directory>
                            <outputDirectory>dist</outputDirectory>
                            <fileMode>644</fileMode>
                            <directoryMode>755</directoryMode>
                          </fileSet>
                        </fileSets>
                      </inline>
                    </assembly>
                    <dockerFile>/Users/transamericamoon/project/src/main/dockerCustomDockerFile</dockerFile>
                  </build>

[codecov]

Codecov Report

Merging #916 into master will decrease coverage by 0.02%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master     #916      +/-   ##
============================================
- Coverage      51.8%   51.78%   -0.03%     
  Complexity     1221     1221              
============================================
  Files           141      141              
  Lines          7161     7164       +3     
  Branches        960      962       +2     
============================================
  Hits           3710     3710              
- Misses         3135     3138       +3     
  Partials        316      316

Impacted Files	Coverage Δ	Complexity Δ
...8/maven/docker/assembly/DockerAssemblyManager.java	17.4% <0%> (-0.22%)	11 <0> (ø)

[rhuss]

Thanks a lot for this PR and the fix ! I adjusted it a bit and integrated into master aleady (19f7892), so I'm closing this PR for now. hope this ok for you ...

Thanks again ...