Node 12 support and bignum -> BigInt

• Node 12 support and bignum -> BigInt

Node 12 support and bignum -> BigInt

• Node 12 support and bignum -> BigInt

Remove moar es6 and add use strict

• Remove moar es6 and add use strict

Removed babel and build step

• Removed babel and build step

Add encrypt method

• Added encrypt method
• Adding missing mocha dependency
• Fix for linting and test compilation

Added test, lint, format, and build

Added test, lint, format, and build