Revert "Need to add @types/node to reg dependencies since we use Error interface"

[adidahiya]

Reverts #1739

[nchen63]

Yeah, it's not the right thing to do, but we should still address this error when compiling when tslint is installed as a library:

node_modules/tslint/lib/configuration.d.ts(1,1): error TS2688: Cannot find type definition file for 'node'.

[adidahiya]

@nchen63 how exactly did you get that error -- did you set up a new test project? We could make a note in the docs

[nchen63]

Yeah, I set up a test project and installed from an npm pack package

[nchen63]

I feel like there should be a way to make it work that doesn't require users to install node typings. Pre-2.0 typescript did not generate the /// <reference types="node" /> header which causes this issue. If we can avoid exporting functions that use the Error interface, that would work too