Create branch for es-x.x versions

(cherry picked from commit aaae6f6)
Update to elasticsearch 1.2.0

Closes #25.

(cherry picked from commit 9f94556)
Race condition: exception while closing the river

Closes #28.

(cherry picked from commit d68f3e7)
Update to elasticsearch 1.3.0

Closes #26.
(cherry picked from commit 06f73b2)
Update to elasticsearch 1.4.0

Closes #27.
(cherry picked from commit b1f34ca)
Update for es 2.0.0
[TEST] add IT test for other wikipedia URL

Closes #29.
(cherry picked from commit e4a5ee9)
Docs: make the welcome page more obvious

BTW, we rename branch 1.4 to 1.x

Closes #30.
update documentation with release 2.3.0
fix typo
Merge pull request #31 from johtani/fix_typo

fix typo
Update to Lucene 4.10.0

Closes #33.