bumps hugo version to match devopsdays-web site

theme previews that we deploy via netlify should use the same version of
Hugo as the devopsdays-web repo so that the previews will accurately
reflect what will ultimately go to production.

ref devopsdays/devopsdays-web@d23d2be

Author: tgross

netlify.toml

@@ -9,10 +9,10 @@
   command = "bin/netlify.sh"
 
 [context.production.environment]
-   HUGO_VERSION = "0.31.1"
+   HUGO_VERSION = "0.46"
 
 [context.deploy-preview.environment]
-  HUGO_VERSION = "0.31.1"
+  HUGO_VERSION = "0.46"
 
 [context.branch-deploy.environment]
-  HUGO_VERSION = "0.31.1"
+  HUGO_VERSION = "0.46"