Version 0.4.0

Major changes:

• Bundle a specific version of ARO with the package instead of downloading it from the internet (ensures reproducibility)
• Add missing ARO mappings to manual curation.
• Command line tool accept database/tool names in case-independent way (by @sebastianLedzianowski)
• lib.map_to_aro returns None if there is no mapping (raises an exception if the name is missing)