v0.4.1

[sstucker]

• Add metaDataTags.remove to complement metaDataTags.add for dealing with unspecified metaDataTags
• Fixed critical _create_dataset bug which prevented saving of unspecified metaDataTags
• Added unspecified metaDataTags test
• lazydocs gen no longer occurs on PR
• Implemented __bool__ for ValidationResult. Considering removing the bool return from Snirf.validate() and validateSnirf