(style) - Removed int return type hint in execute()

This commit removes the int return type hint in lien with PR
feedback comments noting that some users are still using PHP 5.6
and the type hint introduction would be a breakign change.

src/Comcast/PhpLegalLicenses/Command/GenerateCommand.php

@@ -34,7 +34,7 @@ protected function configure()
      *
      * @return void
      */
-    protected function execute(InputInterface $input, OutputInterface $output): int
+    protected function execute(InputInterface $input, OutputInterface $output)
     {
         $this->hideVersion = $input->getOption('hide-version');
         $dependencies = $this->getDependencyList();

src/Comcast/PhpLegalLicenses/Command/ShowCommand.php

@@ -27,7 +27,7 @@ protected function configure()
      *
      * @return void
      */
-    protected function execute(InputInterface $input, OutputInterface $output): int
+    protected function execute(InputInterface $input, OutputInterface $output)
     {
         $dependencies = $this->getDependencyList();
         $this->outputDependencyLicenses($dependencies, $output);