Build with local vulkan data if requested (#319)
This CL adds a flag AMBER_USE_LOCAL_VULKAN which if set when running cmake will have amber use the vulkan header and loaders out of the third_party directory. This should let amber try to build on a system without vulkan so the build can be tested on the bots.
diff --git a/.gitignore b/.gitignore
index 6398fa9..850a919 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
third_party/spirv-tools
third_party/spirv-headers
third_party/vulkan-headers
+third_party/vulkan-loader
.vs
# Vim swap files