doc: update requirement about golang and linux kernel

[fuweid]

Signed-off-by: Wei Fu [email protected]

Ⅰ. Describe what this PR did

Users might run into the issue caused by the kernel. I update the document about the requirement from pouchcontainer. Hope it can help.

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

no need

Ⅳ. Describe how to verify it

NONE

Ⅴ. Special notes for reviews

Next PR will check the plugin status for containerd. If it's not health, we should shutdown the pouchd.

[codecov]

Codecov Report

Merging #2439 into master will increase coverage by 11.5%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2439      +/-   ##
==========================================
+ Coverage   57.26%   68.77%   +11.5%     
==========================================
  Files         277      276       -1     
  Lines       18227    18252      +25     
==========================================
+ Hits        10437    12552    +2115     
+ Misses       6582     4276    -2306     
- Partials     1208     1424     +216

Flag	Coverage Δ
#criv1alpha1test	31.52% <ø> (-0.1%)	⬇️
#criv1alpha2test	35.61% <ø> (-0.13%)	⬇️
#integrationtest	40.1% <ø> (?)
#nodee2etest	32.91% <ø> (-0.21%)	⬇️
#unittest	26.58% <ø> (+0.04%)	⬆️

Impacted Files	Coverage Δ
cri/ocicni/cni_manager.go	59.18% <0%> (-12.25%)	⬇️
storage/volume/modules/tmpfs/tmpfs.go	12.82% <0%> (-3.31%)	⬇️
storage/quota/quota.go	45.04% <0%> (-1.91%)	⬇️
cri/v1alpha2/cri.go	67.51% <0%> (-0.61%)	⬇️
cri/v1alpha2/cri_utils.go	90.92% <0%> (-0.59%)	⬇️
cri/v1alpha1/cri.go	60.59% <0%> (-0.34%)	⬇️
storage/volume/types/meta/meta.go	0% <0%> (ø)	⬆️
cri/v1alpha2/cri_wrapper.go	63.6% <0%> (ø)	⬆️
storage/quota/prjquota.go	27.51% <0%> (ø)	⬆️
storage/quota/grpquota.go	0% <0%> (ø)	⬆️
... and 85 more

[allencloud]

Could you also please change:

// versionExample shows examples in version command, and is used in auto-generated cli docs.
func versionExample() string {
	return `$ pouch version
GoVersion:       go1.9.1
KernelVersion:   3.10.0-693.11.6.el7.x86_64
Os:              linux
Version:         0.1.0-dev
APIVersion:      1.24
Arch:            amd64
BuildTime:       2017-12-18T07:48:56.348129663Z
GitCommit:
`
}

and it will show more official. @fuweid

[allencloud]

LGTM