Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/myclabs/deep-copy/.github/FUNDING.yml

@@ -0,0 +1,12 @@
+# These are supported funding model platforms
+
+github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
+patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: # Replace with a single Ko-fi username
+tidelift: "packagist/myclabs/deep-copy"
+community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+liberapay: # Replace with a single Liberapay username
+issuehunt: # Replace with a single IssueHunt username
+otechie: # Replace with a single Otechie username
+custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

docker/streamline-src/vendor/myclabs/deep-copy/.github/workflows/ci.yaml

@@ -0,0 +1,101 @@
+name: "Continuous Integration"
+
+on:
+  - pull_request
+  - push
+
+env:
+  COMPOSER_ROOT_VERSION: 1.99
+
+jobs:
+  composer-json-lint:
+    name: "Lint composer.json"
+
+    runs-on: "ubuntu-latest"
+
+    strategy:
+      matrix:
+        php-version:
+          - "8.1"
+
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v2"
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+        with:
+          coverage: "none"
+          php-version: "${{ matrix.php-version }}"
+          tools: composer-normalize
+
+      - name: "Get composer cache directory"
+        id: composercache
+        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - name: "Cache dependencies"
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.composercache.outputs.dir }}
+          key: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ matrix.dependencies }}-composer-${{ hashFiles('**/composer.json') }}
+          restore-keys: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ matrix.dependencies }}-composer-
+
+      - name: "Install dependencies"
+        run: "composer update --no-interaction --no-progress"
+
+      - name: "Validate composer.json"
+        run: "composer validate --strict"
+
+      - name: "Normalize composer.json"
+        run: "composer-normalize --dry-run"
+
+  tests:
+    name: "Tests"
+
+    runs-on: "ubuntu-latest"
+
+    strategy:
+      matrix:
+        php-version:
+          - "7.1"
+          - "7.2"
+          - "7.3"
+          - "7.4"
+          - "8.0"
+          - "8.1"
+        dependencies:
+          - "lowest"
+          - "highest"
+
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v2"
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+        with:
+          php-version: "${{ matrix.php-version }}"
+          ini-values: zend.assertions=1
+
+      - name: "Get composer cache directory"
+        id: composercache
+        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - name: "Cache dependencies"
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.composercache.outputs.dir }}
+          key: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ matrix.dependencies }}-composer-${{ hashFiles('**/composer.json') }}
+          restore-keys: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ matrix.dependencies }}-composer-
+
+      - name: "Install lowest dependencies"
+        if: ${{ matrix.dependencies == 'lowest' }}
+        run: "composer update --no-interaction --no-progress --prefer-lowest"
+
+      - name: "Install highest dependencies"
+        if: ${{ matrix.dependencies == 'highest' }}
+        run: "composer update --no-interaction --no-progress"
+
+      - name: "Run tests"
+        timeout-minutes: 3
+        run: "vendor/bin/phpunit"