SCHEMA-893. AsyncHBaseKijiTableWriter#deleteFamily should use mTableName.

In the deleteFamily method in AsyncHBaseKijiTableWriter, a Scanner is
opened using mTable.getName(), which is incorrect. It should use mTableName.

issue: https://jira.kiji.org/browse/SCHEMA-893
Merge pull request #215 from GabeBenjamin/SCHEMA-893

SCHEMA-893. AsyncHBaseKijiTableWriter#deleteFamily should use mTableName...