Revert "Reducing conflicts with other libraries like illuminate/support by wrapping the tap method in a function_exists conditional."

This reverts commit 8d74945.

Author: nateritter

cli/includes/helpers.php

@@ -108,20 +108,18 @@ function should_be_sudo()
     }
 }
 
-if (! function_exists('tap')) {
-    /**
-     * Tap the given value.
-     *
-     * @param  mixed  $value
-     * @param  callable  $callback
-     * @return mixed
-     */
-    function tap($value, callable $callback)
-    {
-        $callback($value);
-
-        return $value;
-    }
+/**
+ * Tap the given value.
+ *
+ * @param  mixed  $value
+ * @param  callable  $callback
+ * @return mixed
+ */
+function tap($value, callable $callback)
+{
+    $callback($value);
+
+    return $value;
 }
 
 /**