Implement module to fetch manifest build artifact.

Query the build internal server to download the manifest.xml
build artifact for a given build and target. Also make the
gitignore non-recursive for build/ so that the build/api dir
is not ignored.
Change-Id: I81ea58f4a83537795ce0b31cb202a6c72f29b840
diff --git a/.gitignore b/.gitignore
index 45fe6e3..fe40911 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,7 +11,7 @@
 # Distribution / packaging
 .Python
 env/
-build/
+/build/
 develop-eggs/
 dist/
 downloads/