Update script that checks copyright years. (#3173)

utils/check_copyright.py

@@ -32,9 +32,9 @@ AUTHORS = ['The Khronos Group Inc.',
            'Google LLC',
            'Pierre Moreau',
            'Samsung Inc']
-CURRENT_YEAR='2019'
+CURRENT_YEAR='2020'
 
-YEARS = '(2014-2016|2015-2016|2016|2016-2017|2017|2017-2019|2018|2019)'
+YEARS = '(2014-2016|2015-2016|2016|2016-2017|2017|2017-2019|2018|2019|2020)'
 COPYRIGHT_RE = re.compile(
         'Copyright \(c\) {} ({})'.format(YEARS, '|'.join(AUTHORS)))