fix: can not handle auto constraints

Author: RobinTheHood

src/Classes/Semver/ConstraintParser.php

@@ -83,6 +83,13 @@ public function parse(string $constraintString): Constraint
             $constraint->version = $version;
             $constraint->versionString = $versionString;
             return $constraint;
+        } elseif (strpos($constraintString, 'auto') === 0) {
+            $constraint->type = Constraint::TYPE_EQUAL;
+            $versionString = substr($constraintString, 1);
+            //$version = $this->parser->parse($versionString);
+            $constraint->version = null; //$version;
+            $constraint->versionString = 'auto';
+            return $constraint;
         }
 
         try {