go-hep/hep: Release v0.9

Release v0.9 is fresh from the oven.

This is a quick and simple release fix with the following main features:

• fix a broken link to the PDF LaTeX example (back from the multi- to mono-repo migration)
• fix a compilation failure in rootio/cmd/root-srv originating from an API modification in a 3rd-party dependency (github.com/satori/go.uuid)

One interesting new feature is the introduction of a simple ROOT::TTree to CSV file conversion command: root2csv.

$> go get go-hep.org/x/hep/cmd/root2csv
$> root2csv --help
root2csv -h
Usage of root2csv:
  -f string
        path to input ROOT file name
  -o string
        path to output CSV file name (default "output.csv")
  -t string
        name of the tree to convert (default "tree")

$> go doc go-hep.org/x/hep/cmd/root2csv 
root2csv converts the content of a ROOT TTree to a CSV file.

    Usage of root2csv:
      -f string
                path to input ROOT file name
      -o string
                path to output CSV file name (default "output.csv")
      -t string
                name of the tree to convert (default "tree")

By default, root2csv will write out a CSV file with ';' as a column
delimiter. root2csv ignores the branches of the TTree that are not supported
by CSV:

    - slices/arrays
    - C++ objects

Example:

    $> root2csv -o out.csv -t tree -f testdata/small-flat-tree.root
    $> head out.csv
    ## Automatically generated from "testdata/small-flat-tree.root"
    Int32;Int64;UInt32;UInt64;Float32;Float64;Str;N
    0;0;0;0;0;0;evt-000;0
    1;1;1;1;1;1;evt-001;1
    2;2;2;2;2;2;evt-002;2
    3;3;3;3;3;3;evt-003;3
    4;4;4;4;4;4;evt-004;4
    5;5;5;5;5;5;evt-005;5
    6;6;6;6;6;6;evt-006;6
    7;7;7;7;7;7;evt-007;7

The next release cycle will see improvements in the rootio department (read and write.)

Stay tuned.