Any action required by this chapter to be taken at a meeting of the shareholders of a corporation, or any action which may be taken at a meeting of the shareholders, may be taken without a meeting if consents in writing, setting forth the action so taken, shall be signed by all of the shareholders entitled to vote with respect to the subject matter thereof. Such consents shall have the same force and effect as a unanimous vote of the shareholders at a meeting duly held, and may be stated as such in any certificate or document filed under this chapter. The secretary shall file such consents with the minutes of the meetings of the shareholders.