Support TypeScript 2.8 in the header language version parser

[fbartho]

1. I wanted to update a project I use type-zoo to use TypeScript language features introduced in TypeScript 2.8.
2. This project depends on dtslint for validating TypeScript Versions
3. Selecting // TypeScript Version 2.8 causes dtslint to fail, which forced me to figure out how dtslint finds language versions, which pointed me to this repo.

• This also fixes a warning in the npm install output.
• This also updates the package-lock.json file as TypeScript has a new next version now.

[msftclas]

All CLA requirements met.

[fbartho]

/cc @Andy-MS -- since you commented on the last version patch :P

[fbartho]

Blocks:

• Feature Request: Support for TypeScript 2.8 dtslint#113
• TypeScript 2.8 — initial support & updates pelotom/type-zoo#14

[pelotom]

Hi, could someone from the TypeScript team look at this? 2.8 has been out for almost a month now and nobody can test typings that rely on conditional types with dtslint because of this.

[pelotom]

Thanks, @Andy-MS!

[fbartho]

Thanks @Andy-MS!

Not to ask more of you, but it looks like you also contribute to dtslint! Would you mind updating the package-lock.json to include this version of definitelytyped-header-parser & deploy a new version of that as well? -- It would fix this issue: microsoft/dtslint#113 and unblock this issue: pelotom/type-zoo#14