Add block-level nodes to every list-item

...and other tiny fixes. This brings the failures down to 2.
Almost there!
Update changelog for 0.1.0-rc.2
0.1.0-rc.2
Remove failing fixtures

There were in fact not "really" failing, they just were impossible
to stringify back to.
Merge branch 'bug/fix-links'
Add benchmark for `mdast.stringify`
Refactor to simplify `spec/mdast.spec.js`
Fix spacing around inline-code containing backticks
Add `.eslintrc`
Refactor to disallow spaces after object keys
Move `benchmark/index.js` to `benchmark.js`
Move `spec/` to `test/`
Move `test/mdast.spec.js` to `test/index.js`
Refactor npm scripts in `package.json`
Update mocha
Update matcha
Update eslint
Add broader version ranges to `package.json`
Refactor `.gitignore`
Refactor `.npmignore`