Remove check on ddl triggers

[ADHUI]

Fixes #25 .

Changes proposed in this pull request:

• Exclude objects where object name is not null. (DDL Triggers)

How to test this code:

• Create a Database Trigger
• Run tSQLt.RunAll when trigger is disabled.

Has been tested on (remove any that don't apply):

• Case-sensitive SQL Server instance
• SQL Server 2008
• SQL Server 2008 R2
• SQL Server 2012
• SQL Server 2014
• SQL Server 2016
• Amazon RDS
• Azure SQL DB

[lastlink]

I would add unit tests for this, github ations now works w/ integrated db tests, see .github/ .yml file