Merge pull request #82 from yyekovenko/master

Added test for Scan operation.
API update
Merge pull request #81 from ikhudoshyn/api-update

API update
Add consistency processing on writes to cassandra

Fixes bug 1271207
Merge pull request #85 from ikhudoshyn/bug/1271207

Add consistency processing on writes to cassandra
Merge pull request #4 from Mirantis/master

Merge with upstream