* lerna bootstrap after install
* set npmClient to default instead of yarn to prevent from causing error with older yarn version
* ref: https://github.com/lerna/lerna/pull/897
* update yarn.lock
* add yarn.lock
* test environment setup with jest
* allow eslint to suit for jest
* run lint before starting testing
* disable deprecated rule of 'react/jsx-space-before-closing'
* add CONTRIBUTING document
* specify how to start testing
* add Enzyme for React testing
* add testing template for bootstrap-table