Updates to 3rd party libraries

Add Dockerfile and specific docker-php.ini

inc/vendor/markbaker/complex/classes/src/functions/negative.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ *
+ * Function code for the complex negative() function
+ *
+ * @copyright  Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
+ * @license    https://opensource.org/licenses/MIT    MIT
+ */
+namespace Complex;
+
+/**
+ * Returns the negative of a complex number.
+ *
+ * @param     Complex|mixed    $complex    Complex number or a numeric value.
+ * @return    float            The negative value of the complex argument.
+ * @throws    Exception        If argument isn't a valid real or complex number.
+ *
+ * @see    rho
+ *
+ */
+function negative($complex)
+{
+    $complex = Complex::validateComplexArgument($complex);
+
+    return new Complex(
+        -1 * $complex->getReal(),
+        -1 * $complex->getImaginary(),
+        $complex->getSuffix()
+    );
+}