Missing @export on h5writeAttribute S3 methods

[LTLA]

This causes problems like:

h5writeAttribute(cn, mat, "dimnames2")
## Error in UseMethod("h5writeAttribute") :
##   no applicable method for 'h5writeAttribute' applied to an object of class "character"

[grimbough]

Thanks for pointing this out. Any idea why it doesn't trip up the unit tests in https://github.com/grimbough/rhdf5/blob/master/tests/testthat/test_h5writeAttributes.R ?

If I run the tests manually I see the error, but its fine in R CMD check or devtools::test(). Either way I'll get it fixed.

[LTLA]

Probably because testthat fiddles with the package namespace to export all of the symbols (including those not exported) when tests are run via test_check(), but not when tests are run manually.