When comparing directories, allow to ignore some specified files #12
Description
Requirement: #11
When comparing a generated directory with a reference one, it should be possible for the developer to specify files to be ignored during the comparison.
For a first step, the files to be ignored could be specified as arguments to the test method which is called. Later on, a file similar to .gitignore could be used to simplify the management of those ignored files.
See Legacy implementation (not sure we want to do it the same way)