bump dep versions

Author: shashi

REQUIRE

@@ -1,8 +1,8 @@
 julia 1.0
 IndexedTables 0.10.0
 TextParse 0.6.0
-MemPool 0.1.1
-Dagger 0.7.3
+MemPool 0.2.0
+Dagger 0.8.0
 Glob 1.2.0
 OnlineStats 0.17.0
 OnlineStatsBase

src/io.jl

@@ -170,13 +170,13 @@ Base.@deprecate ingest!(files, output; kwargs...) loadndsparse(files; output=out
 Load a saved `DNDSparse` from `dir` directory. Data can be saved
 using the `save` function.
 """
-function load(f::AbstractString)
+function load(f::AbstractString; procs=workers())
     if isdir(f)
         x = open(joinpath(f, JULIADB_INDEXFILE)) do io
             deserialize(io)
         end
         _makerelative!(x, f)
-        _evenlydistribute!(x, workers())
+        _evenlydistribute!(x, procs)
         x
     elseif isfile(f)
         MemPool.unwrap_payload(open(deserialize, f))