[testDBTablesAction] Don't use an unnecessary wrapper class.
[testDBTablesAction] Remove an unnecssary class.
[testDBTablesAction] Create instances with a macro.

After DBTablesAction inherits DBTables, we will have to change the
way to make an instance for the test. This macro helps to reduce
lines to be changed when the time comes.
[testDBTablesAction] Remove an unnecessary class.

The class was mistakenly reverted in the previous commit.
Merge pull request #444 from project-hatohol/test-dbtables-action-declare

Test dbtables action declare