Include ArangoDB
Merge pull request #388 from m0ppers/master

Include ArangoDB
removed small bug in List.save()
Merge pull request #390 from jmgunn87/master

removed small bug in List.save()
Added docs for new param
0.2.13
Update schema.md

Minor typos
Merge pull request #397 from neovov/patch-1

Update schema.md
also pass data to beforeValidate hook, even when validation is not set
mark `inst.errors` to null when valid success

Also:
1. make `model.isValid` act like normal node.js async function
2. make `beforeValidate` breakable
return error as null when valid
make all intance method callback has a context of `this` as instance itself
Merge pull request #398 from ktmud/validate

also pass data to `beforeValidate` hook, even when validation is not set
use SVG to display Travis CI build testing status
Merge pull request #403 from Mithgol/use-svg

use SVG to display Travis CI build testing status
make ValidationError more useful

  change message to a errors digest
  capture stack trace
skip filter when "where" is string