When I build my hugo website a “noindex” tag appears in the public files for every page. (Noindex tells search engines to exclude the page)
This is the repo https://github.com/sansculo/otruth
e.g. 
I tried adding robots = “index,follow” to the config file but it didnt change anything i.e. public files still show noindex
Your theme is doing it, in layouts/_default/baseof.html:
{{/* NOTE: For Production make sure you add `HUGO_ENV="production"` before your build command */}}
{{ if eq (getenv "HUGO_ENV") "production" | or (eq .Site.Params.env "production") }}
<META NAME="ROBOTS" CONTENT="INDEX, FOLLOW">
{{ else }}
<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
{{ end }}