v2.4.0

What's Changed

• Added the ability to configure the units system using the config file by @portyanikhin in #15
• Added mass specific volume for the inputs and outputs of fluids, mixtures and humid air by @portyanikhin in #16
• Documentation update by @portyanikhin in #19
• Fixed as_dict and as_json methods by @portyanikhin in #20

Full Changelog: v2.3.2...v2.4.0