Including versions that are not published to npm breaks dtslint

When this package updates to include new versions of the typescript package, and those versions are not published to npm, it causes dtslint not to work.

For example, at the time of this writing, there is no version 3.5 or 3.6 published. However, when dtslint uses TypeScriptVersion.all to seed the generation of package.json files in the installer, those version numbers are used for the typescript dependency, and then npm install ... is run in those directories. This causes dtslint to fail with the following error:

npm ERR! notarget No matching version found for typescript@3.5
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.

This is an important issue for maintainers who use dtslint to verify their type definition files. I happen to maintain @slack/web-api, which depends on dtslint for this reason. We hit this issue here: https://travis-ci.org/slackapi/node-slack-sdk/jobs/538163092.

I'm not sure where else definitelytyped-header-parser is used, so perhaps this is more of an issue for dtslint, but there were no changes in that package which directly caused this issue. Please feel free to close in favor of the issue I will create in that repo as well.

Start in src/installer.ts, especially the TypeScriptVersion.all path that generates package.json files before running npm install. Check how unpublished TypeScript versions enter those dependencies, then verify that dtslint installation no longer requests unavailable versions and completes successfully.