Add future banner config var

Ari Chivukula · Ari Chivukula · commit e4bb53bf037a · 2018-03-20T07:43:27.000-04:00
diff --git a/_config.yml b/_config.yml
@@ -25,3 +25,7 @@ exclude:
   - 'robots.txt-for-beta.code.mil'
   - 'serve'
   - 'vendor'
+
+context:
+  banner:
+    is_dot_mil: True
