Update email address in maintainer file

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Merge pull request #3 from crosbymichael/update-maintainer-email

Update email address in maintainer file
Add build flag for nsenter file
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
Fix vet errors

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Grammar in README
nsenter: fix setns() for rhel6 (glibc-2.12)

Docker-DCO-1.1-Signed-off-by: Vincent Batts <vbatts@redhat.com> (github: vbatts)
Merge pull request #5 from crosbymichael/build-flag

Add build flag for nsenter file
Merge pull request #8 from LK4D4/fix_vet_errors

Fix vet errors
Merge pull request #11 from timthelion/patch-1

Grammar in README
Merge pull request #12 from vbatts/vbatts-fix_setns_rhel6

nsenter: fix setns() for rhel6 (glibc-2.12)