Tweak copyright year in LICENSE
Tweak copyright year in LICENSE

To be consistent with Symfony [LICENSE](https://github.com/symfony/symfony-standard/blob/master/LICENSE)
Codeception/symfony-demo,dzuelke/symfony-demo,dzuelke/symfony-demo,jzawadzki/symfony-demo,vakstk50/jenkinstest,vakstk50/jenkinstest,voronkovich/symfony-demo,bocharsky-bw/symfony-demo,yceruto/symfony-demo,symfony/symfony-demo,bocharsky-bw/symfony-demo,GregSatre/symfony-demo,samitiana/symfony-demo,yodur2potassium/test-behat-selenium-symfo,TomasVotruba/symfony-demo,yodur2potassium/test-behat-selenium-symfo,javiereguiluz/symfony-demo,GregSatre/symfony-demo,mrook/symfony-behat-codeception-demo,samitiana/symfony-demo,vakstk50/jenkinstest,maidmaid/symfony-demo,healthefrog/symfony-demo,nilamkhedkar1/symfony_demo,javiereguiluz/symfony-demo,maidmaid/symfony-demo,Codeception/symfony-demo,GregSatre/symfony-demo,healthefrog/symfony-demo,TomasVotruba/symfony-demo,yceruto/symfony-demo,javiereguiluz/symfony-demo,mrook/symfony-behat-codeception-demo,Codeception/symfony-demo,healthefrog/symfony-demo,yceruto/symfony-demo,nilamkhedkar1/symfony_demo,voronkovich/symfony-demo,nilamkhedkar1/symfony_demo,jzawadzki/symfony-demo,maidmaid/symfony-demo,TomasVotruba/symfony-demo,samitiana/symfony-demo,jzawadzki/symfony-demo,mrook/symfony-behat-codeception-demo,symfony/symfony-demo,GregSatre/symfony-demo,voronkovich/symfony-demo,dzuelke/symfony-demo,bocharsky-bw/symfony-demo,symfony/symfony-demo,yodur2potassium/test-behat-selenium-symfo