Remove unused usings

Author: Kapil Borle

Engine/Generic/ConfigurableScriptRule.cs

@@ -1,10 +1,7 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Management.Automation.Language;
 using System.Reflection;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic
 {

Engine/ScriptAnalyzer.cs

@@ -12,7 +12,6 @@
 //
 
 using System.Text.RegularExpressions;
-using Microsoft.Windows.PowerShell.ScriptAnalyzer.Commands;
 using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;
 using System;
 using System.Collections.Generic;

Rules/PlaceOpenBrace.cs

@@ -18,7 +18,6 @@
 using System.Management.Automation.Language;
 using System.Text;
 using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;
-using System.Reflection;
 
 namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
 {