fwts: 18.02.00 -> 18.03.00

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts -h` got 0 exit code
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts --help` got 0 exit code
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts -V` and found version 18.03.00
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts -v` and found version 18.03.00
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts --version` and found version 18.03.00
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts -h` and found version 18.03.00
- ran `/nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00/bin/fwts --help` and found version 18.03.00
- found 18.03.00 with grep in /nix/store/vvq9vagwr2qzs3xg1ssrkpbiwk6ayq2c-fwts-18.03.00
- directory tree listing: https://gist.github.com/cf8ebe142dd89bc324517d19193e70f4