Got rid of variables, forced terminating PHP process by name before starting another server

.travis.yml

@@ -58,7 +58,6 @@ script:
     else
       cd apps/basic/web
       php -S localhost:8080 > /dev/null 2>&1 &
-      PHP_PID=$!
       cd ../tests
       codecept run
     fi
@@ -66,10 +65,9 @@ script:
     if (php --version | grep -i HipHop > /dev/null); then
       echo "Skipping advanced application tests on HHVM"
     else
-      kill -9 $PHP_PID
+      kill $(ps -ef | grep php | awk '{print $2}')
       cd ../../advanced
       php -S localhost:8080 > /dev/null 2>&1 &
-      PHP_PID=$!
       cd tests
       codecept run
     fi