Release v2.1.0

Bug Fixes

• remove unnecessary checks (1bbad3a)
• lint: fix eslint (caeac70)
• types: fix encoding type (cdc6958)
• change build status ref to GitHub (5b0e6fc)
• improve checking of Hashable applicant (3856207)

Features

• add Hashable interface (9006c13)
• added warnings to eslint errors (422c893)
• fixed eslint errors (e9245f7)
• fixed npm script issue (0bf8c17)
• updated typescript, migrated to tslint (3a40fcc)