Add ci function

The ci function adds confidence interval and
relative frequencies to a table.

Change-Id: Id702522d35e557f20540bc24301195d0513b7138
diff --git a/NAMESPACE b/NAMESPACE
index 3074a48..3488a72 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -2,11 +2,15 @@
 
 S3method(format,KorAPQuery)
 export("%>%")
+export(as_tibble)
+export(bind_cols)
+export(ci)
 export(complete)
 export(group_by)
 export(mutate)
 export(select)
 export(summarise)
+export(tidy)
 export(year)
 exportClasses(KorAPConnection)
 exportClasses(KorAPCorpusStats)
@@ -27,6 +31,7 @@
 import(purrr)
 import(tidyr)
 import(utils)
+importFrom(broom,tidy)
 importFrom(dplyr,group_by)
 importFrom(dplyr,mutate)
 importFrom(dplyr,select)
@@ -34,4 +39,5 @@
 importFrom(jsonlite,fromJSON)
 importFrom(lubridate,year)
 importFrom(magrittr,"%>%")
+importFrom(stats,prop.test)
 importFrom(tidyr,complete)