Import latest app updates from streamline

An updated set of source files and initialization was provided by streamline to
address issues observed during initial testing. These files have been updated in
order to generate a new set of app images.

docker/streamline-src/vendor/guzzlehttp/psr7/src/DroppingStream.php

@@ -1,49 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace GuzzleHttp\Psr7;
-
-use Psr\Http\Message\StreamInterface;
-
-/**
- * Stream decorator that begins dropping data once the size of the underlying
- * stream becomes too full.
- */
-final class DroppingStream implements StreamInterface
-{
-    use StreamDecoratorTrait;
-
-    /** @var int */
-    private $maxLength;
-
-    /** @var StreamInterface */
-    private $stream;
-
-    /**
-     * @param StreamInterface $stream    Underlying stream to decorate.
-     * @param int             $maxLength Maximum size before dropping data.
-     */
-    public function __construct(StreamInterface $stream, int $maxLength)
-    {
-        $this->stream = $stream;
-        $this->maxLength = $maxLength;
-    }
-
-    public function write($string): int
-    {
-        $diff = $this->maxLength - $this->stream->getSize();
-
-        // Begin returning 0 when the underlying stream is too large.
-        if ($diff <= 0) {
-            return 0;
-        }
-
-        // Write the stream or a subset of the stream if needed.
-        if (strlen($string) < $diff) {
-            return $this->stream->write($string);
-        }
-
-        return $this->stream->write(substr($string, 0, $diff));
-    }
-}