vagrant: make sure to bootstrap before configure_ovs.

vagrant: make sure to bootstrap before configure_ovs.

The order of execution in Vagrantfile is "outside-in" meaning that
all commands in outer scope are executed first and then the commands
in inner scope. Because of this ordering, "configure_ovs" is executed
before "bootstrap_fedora", resulting in "configure_ovs" to fail as
it is not bootsrapped yet. This change fixes this problem by removing
the nested scope in Vagrant.configure block. Multi-machine is not used
so we don't need config.vm.define block.

Signed-off-by: Motonori Shindo <motonori@shin.do>
Signed-off-by: Thomas Graf <tgraf@noironetworks.com>