Require generateContainerSpec passes during tests and abort if not
Require generateContainerSpec passes during tests and abort if not

This is achieved by switching `assert.NoError` to `require.NoError` in several
places.

Otherwise the test code will continue and dereference a nil spec, leading to a
panic which obscures the real failure.

Signed-off-by: Ian Campbell <a8db091655a7f47ecb9c39a2d278e9662e440dc0@docker.com>

dmcgowan/containerd,vdemeester/containerd,containerd/containerd,w9n/cri-containerd,thaJeztah/containerd,thaJeztah/containerd,vdemeester/containerd,estesp/containerd,zhangzhenhao/cri-containerd,dmcgowan/containerd,w9n/cri-containerd,zhangzhenhao/cri-containerd,mikebrow/containerd,mikebrow/cri-containerd,mikebrow/cri-containerd,mikebrow/cri-containerd,estesp/containerd,w9n/cri-containerd,mikebrow/containerd,zhangzhenhao/cri-containerd,containerd/containerd