Fix mac issues

Author: exussum12

build.sh

@@ -6,7 +6,7 @@ git log origin/master... | grep -q SKIP_BUILD && exit 0
 [ -z "$UPDATE_COVERAGE" ] || composer require satooshi/php-coveralls:v1.1.0
 
 composer install
-git diff $(git merge-base origin/master HEAD) > diff.txt
+[ -z "$UPDATE_COVERAGE" ] || git diff $(git merge-base origin/master HEAD) > diff.txt
 phpcs --standard=psr2 src
 phpcs --standard=psr2 --ignore=bootstrap.php,fixtures/* tests
 
@@ -15,6 +15,6 @@ phpmd tests text cleancode,codesize,controversial,unusedcode --exclude fixtures
 
 ./vendor/bin/phpunit
 
-bin/diffFilter --phpunit diff.txt report/coverage.xml
+[ -z "$UPDATE_COVERAGE" ] || bin/diffFilter --phpunit diff.txt report/coverage.xml
 
 [ -z "$UPDATE_COVERAGE" ] || php vendor/bin/coveralls -v