Don't keep type safety then. Think of Go as half-way between Python and Haskell in that respect. Types are great when they're useful, but they're not required.
That’s the same mistake C did with void, Java did with Object and corrected with generics in 1.5, just called interface{} this time.
And while with python and Java, even if I circumvent the type system, I can still use annotations (see typed python, or JetBrains @Contract, Google’s @IntRange, etc), with Go I have nothing of that sort.
Types are useful to provide safety, if your type system has to be turnt off, then I am losing all that safety, and might as well code in PHP (although they also* saw that mistake, and are fixing it now, with 7.0 and later).