[#2699] Only run php-cs-fixer on bin, library, and tests

- demos directory contains some embedded javascript code that php-cs-fixer does
  not like

.travis.yml

@@ -12,7 +12,9 @@ before_install:
 
 script:
  - php ./tests/run-tests.php
- - output=$(php php-cs-fixer.phar fix -v --dry-run --level=psr2 .); if [[ $output ]]; then while read -r line; do echo -e "\e[00;31m$line\e[00m"; done <<< "$output"; false; fi;
+ - output=$(php php-cs-fixer.phar fix -v --dry-run --level=psr2 library); if [[ $output ]]; then while read -r line; do echo -e "\e[00;31m$line\e[00m"; done <<< "$output"; false; fi;
+ - output=$(php php-cs-fixer.phar fix -v --dry-run --level=psr2 tests); if [[ $output ]]; then while read -r line; do echo -e "\e[00;31m$line\e[00m"; done <<< "$output"; false; fi;
+ - output=$(php php-cs-fixer.phar fix -v --dry-run --level=psr2 bin); if [[ $output ]]; then while read -r line; do echo -e "\e[00;31m$line\e[00m"; done <<< "$output"; false; fi;
 
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