Bounds variable search assumes time dimension name

[angus-g]

In the following code segment, the search for relevant bounds variables hard-codes the name of the time dimension as time, but this isn't always the case. Perhaps this should use cc.netcdf_utils.find_time_dimension?

cosima-cookbook/cosima_cookbook/querying.py

Lines 420 to 422 in ac2d674

	bounds_var = ncfile.ncvars["time"].attrs.get("bounds")
	if bounds_var is not None:
	variables.append(bounds_var)