Merge pull request #169 from embulk/add-column-options-doc

Update README. Add the `TIME` type in a column_options

Author: hiroyuki-sato

README.md

@@ -325,8 +325,8 @@ Column options are used to aid guessing BigQuery schema, or to define conversion
     - boolean:   `BOOLEAN`, `STRING` (default: `BOOLEAN`)
     - long:      `BOOLEAN`, `INTEGER`, `FLOAT`, `STRING`, `TIMESTAMP` (default: `INTEGER`)
     - double:    `INTEGER`, `FLOAT`, `STRING`, `TIMESTAMP` (default: `FLOAT`)
-    - string:    `BOOLEAN`, `INTEGER`, `FLOAT`, `STRING`, `TIMESTAMP`, `DATETIME`, `DATE`, `RECORD` (default: `STRING`)
-    - timestamp: `INTEGER`, `FLOAT`, `STRING`, `TIMESTAMP`, `DATETIME`, `DATE` (default: `TIMESTAMP`)
+    - string:    `BOOLEAN`, `INTEGER`, `FLOAT`, `STRING`, `TIME`, `TIMESTAMP`, `DATETIME`, `DATE`, `RECORD` (default: `STRING`)
+    - timestamp: `INTEGER`, `FLOAT`, `STRING`, `TIME`, `TIMESTAMP`, `DATETIME`, `DATE` (default: `TIMESTAMP`)
     - json:      `STRING`,  `RECORD` (default: `STRING`)
   - **mode**: BigQuery mode such as `NULLABLE`, `REQUIRED`, and `REPEATED` (string, default: `NULLABLE`)
   - **fields**: Describes the nested schema fields if the type property is set to RECORD. Please note that this is **required** for `RECORD` column.