fix: allow paths with hyphens #91
                
     Merged
            
            
          
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
While trying to create a diagram of a complete application, I've noticed that PlantUml has problems if any file path includes dashes. For example, If you have a folder like this:
PlantUml will throw an error at the line referencing app_package-with-hyphens_ClassA
With this pull request I've made a minimal change to correct this, but I'm not able to write a unit test that doesn't involve testing many parts of php-class-diagram because I have to instantiate several internal classes. I could use some help testing this change.
Thanks a lot