Generate version.ts before publish to NPM

[huan]

Currently, we are using read-pkg-up to load module version at run time.

There has a discussion between @footballencarta and me before, at huan/rx-queue#25 (comment), I agree with most of his options and I decide to generate a static for our modules to prevent some strange bugs.

The most recent bug I had experienced is that the read-pkg-up package API had a breaking change, which causes a log problem in our Chatie ecosystem because I'm heavy depended on it.

So what I'm planning to do, is:

1. Create a dummy src/version.ts file only export const VERSION = '0.0.0'
2. Add a unit test to make sure the VERSION exported from version.ts is equal to 0.0.0
3. Add a scripts/generate-version.ts to generate src/version.ts file
4. Run scripts/generate-version.ts right before npm run dist in Travis CI
5. So that we can save the version number to our module before npm publish

[huan]

Close this issue because it had been implmented.