Snowflake/driver class (#865)

* snowflake(): instantiates object inheriting from OdbcDriver

* roxygenize

---------

Co-authored-by: simonpcouch <simonpatrickcouch@gmail.com>

Author: detule

NAMESPACE

@@ -44,6 +44,7 @@ exportClasses(PostgreSQL)
 exportClasses(Redshift)
 exportClasses(SQLite)
 exportClasses(Snowflake)
+exportClasses(SnowflakeOdbcDriver)
 exportClasses(Teradata)
 exportMethods(dbAppendTable)
 exportMethods(dbBegin)

R/driver-snowflake.R

@@ -152,13 +152,17 @@ setMethod("odbcDataType", "Snowflake",
 #' }
 #' @export
 snowflake <- function() {
-  new("Snowflake")
+  new("SnowflakeOdbcDriver")
 }
 
+#' @rdname snowflake
+#' @export
+setClass("SnowflakeOdbcDriver", contains = "OdbcDriver")
+
 #' @rdname snowflake
 #' @export
 setMethod(
-  "dbConnect", "Snowflake",
+  "dbConnect", "SnowflakeOdbcDriver",
   function(drv,
            account = Sys.getenv("SNOWFLAKE_ACCOUNT"),
            driver = NULL,