Merge pull request #172 from dmitry-sinina/application_octet_stream

allow application/octet-stream content-type

Author: Fivell

lib/active_admin_import/model.rb

@@ -21,6 +21,7 @@ module CONST
         application/csv
         application/vnd.ms-excel
         application/vnd.msexcel
+        application/octet-stream
         text/tsv
         text/x-tsv
         text/tab-separated-values