ts-node fails on composite projects

[sgoll]

Running ts-node fails when the tsconfig.json file contains the new attribute "composite": true (microsoft/TypeScript#25600).

The error message is as follows:

TSError: ⨯ Unable to compile TypeScript:
error TS6304: Composite projects may not disable declaration emit.

The reason for this is that ts-node explicitly removes declaration from the TypeScript configuration but leaves composite intact, hence TypeScript complaining about this invalid combination.

The fix would be to adjust the fixConfig function to also always remove composite from the TypeScript configuration.

[blakeembrey]

Closed with #657.