Update layouts/index.html

Co-authored-by: Scott Anderson <[email protected]>

Author: jstirnaman

layouts/index.html

@@ -11,7 +11,7 @@
   - This is a regular page (not test-only) OR
   - This is a test-only page BUT we're currently in the testing environment
 -->
-{{ if or (not .Params.test_only) (and .Params.test_only (eq site.Params.environment "testing")) }}
+{{ if or (not .Params.test_only) (and .Params.test_only (in site.Params.environment (slice "testing" "development")) }}
 
 {{ partial "header.html" . }}
 {{ partial "topnav.html" . }}