[Tryfix] Increase the default RAM in vagrantfile
[Tryfix] Increase the default RAM in vagrantfile

When I create two containers and one tiny vm, I find the
neutron-ovs-agent is crash due to lack of memory. I know
we can add memory by modify VAGRANT_KURYR_VM_MEMORY. But
I think create two containers and one tiny vm is very
basic requirement when test kuryr, the default ram should
support this.

Change-Id: I6758ffb104d8ed91135ec58b0c2b794e7fce10c9
Closes-Bug: #1582716

celebdor/kuryr-libnetwork,celebdor/kuryr,openstack/kuryr,celebdor/kuryr-libnetwork,celebdor/kuryr,celebdor/kuryr-libnetwork,openstack/kuryr