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/public/elite/bootstrap/grunt/sauce_browsers.yml

@@ -0,0 +1,82 @@
+[
+  # Docs: https://saucelabs.com/docs/platforms/webdriver
+
+  {
+    browserName: "safari",
+    platform: "OS X 10.10"
+  },
+  {
+    browserName: "chrome",
+    platform: "OS X 10.10"
+  },
+  {
+    browserName: "firefox",
+    platform: "OS X 10.10"
+  },
+
+  # Mac Opera not currently supported by Sauce Labs
+
+  {
+    browserName: "internet explorer",
+    version: "11",
+    platform: "Windows 8.1"
+  },
+  {
+    browserName: "internet explorer",
+    version: "10",
+    platform: "Windows 8"
+  },
+  {
+    browserName: "internet explorer",
+    version: "9",
+    platform: "Windows 7"
+  },
+  {
+    browserName: "internet explorer",
+    version: "8",
+    platform: "Windows 7"
+  },
+
+  # { # Unofficial
+  #   browserName: "internet explorer",
+  #   version: "7",
+  #   platform: "Windows XP"
+  # },
+
+  {
+    browserName: "chrome",
+    platform: "Windows 8.1"
+  },
+  {
+    browserName: "firefox",
+    platform: "Windows 8.1"
+  },
+
+  # Win Opera 15+ not currently supported by Sauce Labs
+
+  {
+    browserName: "iphone",
+    platform: "OS X 10.10",
+    version: "8.2"
+  },
+
+  # iOS Chrome not currently supported by Sauce Labs
+
+  # Linux (unofficial)
+  {
+    browserName: "chrome",
+    platform: "Linux"
+  },
+  {
+    browserName: "firefox",
+    platform: "Linux"
+  }
+
+  # Android Chrome not currently supported by Sauce Labs
+
+  # { # Android Browser (super-unofficial)
+  #   browserName: "android",
+  #   version: "4.0",
+  #   platform: "Linux"
+  # }
+]