v1.6.0

• Customize allowed attributes per class (#115)
• make ambiguous class check a warning (#107)
• Fix some es5 incompatbilities introduced in v1.5.2 (#110)
• Exclude Error#stack by default (#111)
• Fix bug where nested classes weren't transformed (#112)

Meta

• Add @simonedelmann as contributor
• Add @samtgarson as contributor
• Add @markhughes as contributor