Any and all negotiable coupon bonds authorized by any county, city, town, or school district in the state of Colorado prior to March 29, 1917, which might be invalid by reason of the debt-limiting or tax-limiting provisions of section 29-1-301, C.R.S., are validated as fully and completely as if said section and the amendments thereof had never been made a part thereof.
C.R.S. § 30-25-203