fixed rspec error.
fixed ActiveRecord::RecordNotFound error when we create collaborator.
do not use gravatar and baidu map in test enviroment.
Merge pull request #563 from saberma/saberma/fixed-rspec-error

修正 travis-ci 随机出现的几个问题
Merge pull request #564 from saberma/saberma-enhancement/stub-gravatar-and-baidu-map-in-test

测试环境不使用 gravatar 和 百度地图
use parallel bundler.
use j8.
use j16.
remove unneccessary bin files.
revert to use j8.
use bundle instead of bundler command in travis.yml
Merge pull request #565 from saberma/saberma-enhancement/use-parallel-bundler

使用并发 bundler