Make crictl and critest statically linked.

[Random-Liu]

Make crictl and critest statically linked.

This makes is possible to use crictl inside container. (See kubernetes/kubernetes#63355)
This also makes the binary smaller.

Statically linked binary:

$ ls -alh $GOPATH/bin/crictl
-rwxr-x--- 1 lantaol primarygroup 26M May  2 02:11 /usr/local/google/home/lantaol/workspace/bin/crict

Dynamically linked binary:

$ ls -alh $GOPATH/bin/crictl
-rwxr-x--- 1 lantaol primarygroup 28M May  2 02:12 /usr/local/google/home/lantaol/workspace/bin/crictl

Signed-off-by: Lantao Liu lantaol@google.com

[feiskyer]

/lgtm