Just forget to add deploy_key to this repository.

to restore successful build status. travis DOCS job on master failed due to permisstion issue: https://travis-ci.org/baidu/Paddle/jobs/159851334  @reyoung, please resolve the permission issue.

* Add documentation build to ci test
* Push master branch doc changes to gh-pages branch

* install wheels when invoke paddle script if current python don't
  have paddle packages, or installed a previous version.
* Also add `make install` to travis

git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1461 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4600925


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1443 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4600307


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1439 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4600057



git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1438 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4599563


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1435 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4599521


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1434 1ad973e4-5ce8-4261-8a94-b56d1f490c56

Maybe is disk usage issue.

ISSUE=4596347


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1426 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4590133


git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1418 1ad973e4-5ce8-4261-8a94-b56d1f490c56

to fit hub.docker.com

ISSUE=4589547



git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1417 1ad973e4-5ce8-4261-8a94-b56d1f490c56

ISSUE=4586495

git-svn-id: https://svn.baidu.com/idl/trunk/paddle@1408 1ad973e4-5ce8-4261-8a94-b56d1f490c56