Update 2021 copyright dates

Author: BrentOzar

LICENSE.md

@@ -3,13 +3,13 @@ MIT License
 Copyright for portions of sp_Blitz are held by Microsoft as part of project 
 tigertoolbox and are provided under the MIT license:
 https://github.com/Microsoft/tigertoolbox
-All other copyrights for sp_Blitz are held by Brent Ozar Unlimited, 2020 as
+All other copyrights for sp_Blitz are held by Brent Ozar Unlimited, 2021 as
 described below.
 
 Copyright for portions of DatabaseRestore are held by GregWhiteDBA as part
 of project MSSQLAutoRestore and are provided under the MIT license:
 https://github.com/GregWhiteDBA/MSSQLAutoRestore
-All other copyrights for DatabaseRestore are held by Brent Ozar Unlimited, 2020
+All other copyrights for DatabaseRestore are held by Brent Ozar Unlimited, 2021
 as described below.
 
 Copyright for sp_BlitzInMemoryOLTP are held by Ned Otter and Konstantin
@@ -21,7 +21,7 @@ project SqlServerVersionScript and are provided under the MIT license:
 https://github.com/jadarnel27/SqlServerVersionScript
 
 
-Copyright (c) 2020 Brent Ozar Unlimited
+Copyright (c) 2021 Brent Ozar Unlimited
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal