This commit adds all cadvisor dependencies as the result of running
the following commands:
go get -u
godep save
The .travis.yml file has been updated to use godep for building
binaries and running tests. The prepare.sh script has been updated
to use godep to build the cadvisor binary.
Remove old Dockerfiles for deployment and create a new one that only
includes the statically linked binaries we need. This creates an image
that is ~22MB in size.