plantuml: 1.2017.18 -> 1.2018.8

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/plantuml/versions.

These checks were done:

- built on NixOS
- /nix/store/zw5saa1f4fz5ryy36y8wbfsk4d1d4zj2-plantuml-1.2018.8/bin/plantuml passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 1.2018.8 with grep in /nix/store/zw5saa1f4fz5ryy36y8wbfsk4d1d4zj2-plantuml-1.2018.8
- directory tree listing: https://gist.github.com/17d4e9eff9780c3888b753dd532d69a6
- du listing: https://gist.github.com/e697713d2172debdd01e478d01f8505f

pkgs/tools/misc/plantuml/default.nix

@@ -1,12 +1,12 @@
 { stdenv, fetchurl, jre, graphviz }:
 
 stdenv.mkDerivation rec {
-  version = "1.2017.18";
+  version = "1.2018.8";
   name = "plantuml-${version}";
 
   src = fetchurl {
     url = "mirror://sourceforge/project/plantuml/${version}/plantuml.${version}.jar";
-    sha256 = "0ssfg6lpk41ydhxhi6y6c9ca3hpql6gg3bxjws8vrx9s3s6r5rb0";
+    sha256 = "02svd0cpaix2d523iy457h3qwlc9qpvvkls64bqa7yrqyk43xrii";
   };
 
   # It's only a .jar file and a shell wrapper