column_info test inconsistent with spec

[imanuelcostigan]

DBI::dbColumnInfo help:

Value: A data.frame with one row per output field in res. Methods MUST include name, field.type (the SQL type), and data.type (the R data type) columns, and MAY contain other database specific information like scale and precision or whether the field can store NULLs.

This means the number of columns of the resulting col info data frame does not have to be two, whereas, in DBItest:

 ci <- dbColumnInfo(res)
expect_identical(colnames(ci), c("name", "type"))

And also, the name of the type field is assumed to be type rather than field.type per doc:

 expect_is(ci$type, "character")

Let me know if I have interpreted this correctly and if you would like me to either submit a PR:

1. To change the DBI spec
2. Correct the DBItest cases

[krlmlr]

Thanks. I'll be fixing dbColumnInfo() specs soon, will take care of it. Would you like to comment on r-dbi/DBI#75?

[krlmlr]

Closing in favor of r-dbi/DBI#75.