add member stats history/distribution/activeChallenges

[zjuasmn]

For topcoder-platform/community-app#868

[ThomasKranitsas]

@birdofpreyru can you please merge this? I don't have write access on this repo

[birdofpreyru]

@ThomasKranitsas Congrats, you have write access to this repo ;)
Just be sure to properly manage version tags, and update CHANGELOG, especially for any breaking changes

[birdofpreyru]

Ah... well, I guess, write access still does not let you to push to master, thus release updates to npm

[ThomasKranitsas]

Thanks! Any instructions regarding version tags/changelog? I've never done that before :)

[birdofpreyru]

• To bump version in package.json and package-lock.json do one of these:

  $ npm version patch --no-git-tag - to bump the last digit - when you want to get it to npm, and you are sure that changes from the previous version do not introduce any breaking changes;

  $ npm version minor --no-git-tag - to bump the middle digit, and set the last one to zero - when you suspect that there might be breaking changes.

  The version should be bumped in develop branch, then to publish to npm it should merged into master and taged with the version number, prefixed by v, like v0.1.2. CircleCI releases to NPM results of tag builds.

• In CHANGELOG.md we should keep summary of updates introduced between versions. In case of small updates, it just summaries descriptions of related git commits (in case there many git commits between versions, it is easier to read changelog, than track all commits). But more important is: if version introduces some breaking changes, that requires code updates in other libs / apps depending on the library, then records in changelog should instruct what exactly and how should be updated in such code.