Fix command used to detect version

[kostyrev]

Without this fix error Error: unknown flag: --version occurs.

What this PR does / why we need it:
This PR improves docs
Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

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[k8s-reviewable]

This change is 

[coveralls]

Coverage remained the same at 36.13% when pulling 58c8bfd on kostyrev:master into e4c8488 on kubernetes:master.

[aledbf]

/lgtm

[aledbf]

@kostyrev thanks!