* Update ESLint to 3.10.2
Also pull in fbjs for extending properly, per @zpao. This also disables consistent-return, which has about 80 failing cases in React currently. If we'd like to turn this back on, we should do it separately and fix all the call sites properly (rather than just adding 'return undefined;' everywhere, which adds no value.
Fixes to all existing lint errors plus an update for yarn.lock to follow.
* Update yarn.lock after the eslint update.
* Fix all new eslint failures
Unfortunately I had to add three eslint-disable-next-line instances. All have explanations inline.
* Switch Travis to use yarn instead of npm
* Introduce facts-tracker
We want to be able to track various things like number of files that are flowified, number of tests passing with Fiber...
This introduces a tool that lets you do that. The API is very simple, you execute the script with a list of tuples [key value] and it's going to create a `facts` branch and put a txt file for each fact and values over time.
```
node scripts/facts-tracker/index.js \
"flow-files" "$COUNT_WITH_FLOW/$COUNT_ALL_FILES"
```
Test Plan:
This is tricky to test because Travis only exposes the private variables (github token) when it processes a committed file and not on branches. The reason is that otherwise anyone could send a pull requests that does `echo $GITHUB_TOKEN` and steal your token.
Given this constraint, I did all the work using two of my repos:
- https://github.com/vjeux/facts-tracker
- https://github.com/vjeux/facts-tracker-test
and am sending this pull request that should work as is /fingers crossed/, but we won't be able to test it out until it is committed.
Note that once this lands, I'm going to kill those two repos.
* Update with all the suggested changes
* Branch on a flow type in travis.yml
* Use $GITHUB_TOKEN
* properly escape it
