Fix typescript build script; merge master; update deps

[tedbyron]

• fixed package.json build script to output typescript declaration file
• merged master
• updated vulnerable dependencies

fixes #64

[tedbyron]

@Findus23 you just needed to remove the filename from tsc command, tsc will only generate declarations when compiling the entire lib (even though that's the only ts file)

[Findus23]

Thanks for the hint. I'll try updating all modules and publish another version.

[Findus23]

I published 3.0.0-beta.3 including this change (and run with just tsc)