update README.md to include Docker and not needing external source for xenial

diff --git a/README.md b/README.md
index f02ca48f77c7580e7b3a13869f5eb48554ad4508..6816315669730a1c4122ac048341658c597d401a 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,20 +1,19 @@
 # Vulkan-cpu
 
+[![Build Status](https://travis-ci.org/programmerjake/vulkan-cpu.svg?branch=master)](https://travis-ci.org/programmerjake/vulkan-cpu)
+
 Work-in-progress for Vulkan implementation on cpu
 
+## Build in Docker
+
+    docker build -t vulkan-cpu .
+
 ## Build under Ubuntu 16.04 (xenial)
 
-    sudo apt install software-properties-common wget
-    wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-    sudo apt-add-repository 'deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-4.0 main'
-    sudo apt update
-    sudo apt install build-essential git clang-4.0 llvm-4.0-dev cmake zlib1g-dev
+    sudo apt install build-essential git clang-4.0 llvm-4.0-dev cmake zlib1g-dev libsdl2-dev
     git clone https://github.com/programmerjake/vulkan-cpu.git
     cd vulkan-cpu
     mkdir build
     cd build
     cmake .. -DCMAKE_CXX_COMPILER="`which clang++-4.0`" -DCMAKE_C_COMPILER="`which clang-4.0`" -DCMAKE_BUILD_TYPE=Debug
     make
-
-Using the version of LLVM 3.8 that comes with Ubuntu doesn't work.  
-See [Issue #1](https://github.com/programmerjake/vulkan-cpu/issues/1) for more details.