Vectorize corpusQuery and corpusStats

Change-Id: If2deeeeef2b2d64169dd21e5514dac6f8e458b32
diff --git a/NAMESPACE b/NAMESPACE
index 3488a72..a34e671 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -6,6 +6,7 @@
 export(bind_cols)
 export(ci)
 export(complete)
+export(expand_grid)
 export(group_by)
 export(mutate)
 export(select)
@@ -27,11 +28,13 @@
 import(R.cache)
 import(dplyr)
 import(httr)
+import(jsonlite)
 import(methods)
 import(purrr)
 import(tidyr)
 import(utils)
 importFrom(broom,tidy)
+importFrom(dplyr,bind_cols)
 importFrom(dplyr,group_by)
 importFrom(dplyr,mutate)
 importFrom(dplyr,select)
@@ -40,4 +43,7 @@
 importFrom(lubridate,year)
 importFrom(magrittr,"%>%")
 importFrom(stats,prop.test)
+importFrom(tibble,as_tibble)
+importFrom(tibble,rownames_to_column)
 importFrom(tidyr,complete)
+importFrom(tidyr,expand_grid)