Perf Test fixing bugs and Update command (#155)

* Fixed some bugs caused by rafactoring

* Verifying a test db is created before running the tests

test/Microsoft.SqlTools.ServiceLayer.TestDriver/Scripts/CreateTestDatabase.sql

@@ -0,0 +1,13 @@
+USE master
+GO
+
+DECLARE @dbname nvarchar(128)
+SET @dbname = N'#DatabaseName#'
+
+IF NOT(EXISTS (SELECT name 
+FROM master.dbo.sysdatabases 
+WHERE ('[' + name + ']' = @dbname 
+OR name = @dbname)))
+BEGIN
+	CREATE DATABASE #DatabaseName#
+END