Update alembic requirement to 0.6.0 version

Our ceilometer/storage/sqlalchemy/alembic/versions/b6ae66d05e3_remove_extra_indexes.py
call a new drop_constraint method with type_ argument,
but this new method argument is invovled from alembic 0.5.0 version,
and Jenkins is using alembic 0.6.0 version, global-requirements.txt
changed by 46004 patch already.

Fixed bug: 1221467

Change-Id: Iecdc453acc5fdbad28141e3c882df2f7006d5205
Update sphinxcontrib-pecanwsme to 0.3

The 0.3 release removes the use of pbr for packaging.

Change-Id: I18ae5306580a51655f93ef5b534aa9087c45bf2b
Merge "Update sphinxcontrib-pecanwsme to 0.3"
Merge "Update alembic requirement to 0.6.0 version"