Update copyright checker for 2019 (#2256)

diff --git a/utils/check_copyright.py b/utils/check_copyright.py
index 85ea128..fc249e9 100755
--- a/utils/check_copyright.py
+++ b/utils/check_copyright.py
@@ -32,9 +32,9 @@
            'Google Inc.',
            'Google LLC',
            'Pierre Moreau']
-CURRENT_YEAR='2018'
+CURRENT_YEAR='2019'
 
-YEARS = '(2014-2016|2015-2016|2016|2016-2017|2017|2018)'
+YEARS = '(2014-2016|2015-2016|2016|2016-2017|2017|2018|2019)'
 COPYRIGHT_RE = re.compile(
         'Copyright \(c\) {} ({})'.format(YEARS, '|'.join(AUTHORS)))