warn -> @warn

Author: joshday

docs/src/missing_values.md

@@ -1,5 +1,6 @@
 ```@setup dv
-using JuliaDB
+using JuliaDB, Pkg
+Pkg.add("DataValues")
 ```
 
 # Missing Values

src/io.jl

@@ -218,10 +218,13 @@ end
 function _makerelative!(t, dir::AbstractString)
     foreach(t.chunks) do c
         h = c.handle
+        @info "_makerelative! handle: $h"
         if isa(h, FileRef)
+            @info "set handle to FileRef"
             c.handle = FileRef(joinpath(dir, h.file), h.size)
         end
     end
+    @info "finished foreach"
 end
 
 using MemPool

src/util.jl

@@ -135,7 +135,7 @@ function _loadtable_serial(T, file::Union{IO, AbstractString, AbstractArray};
         nullableidx = findall(x->eltype(x) <: Union{DataValue,Nullable} || Missing <: eltype(x), indexvecs)
         if !isempty(nullableidx)
             badcol_names = header[_indexcols[nullableidx]]
-            warn("Indexed columns may contain Nullables or NAs. Column(s) with nullables: $(join(badcol_names, ", ", " and ")). This will result in wrong sorting.")
+            @warn("Indexed columns may contain Nullables or NAs. Column(s) with nullables: $(join(badcol_names, ", ", " and ")). This will result in wrong sorting.")
         end
 
         index = Columns(Tuple(indexvecs); names=indexcolnames)