chore(sys): remove obsolete/broken nix/travis/git configuration

sys/.gitignore

@@ -1,3 +0,0 @@
-target
-Cargo.lock
-/tmp

sys/.travis.yml

@@ -1,38 +0,0 @@
-sudo: required
-language: rust
-rust:
-  - stable
-  - beta
-  - nightly
-os:
-  - linux
-  - os: osx
-    osx_image: xcode12.5
-matrix:
-  allow_failures:
-    - rust: nightly
-addons:
-  apt:
-    packages:
-      - build-essential
-before_install:
-  # Without rustfmt, bindgen puts everything on one line and any warnings dump so many logs they break Travis
-  # See https://github.com/rust-lang/rust-bindgen/issues/1600
-  # optional, because nightlies may not have it
-  - rustup component add rustfmt || true
-  - if [[ $TRAVIS_OS_NAME == 'linux' ]]; then ./.travis/install_linux.sh; fi
-  - if [[ $TRAVIS_OS_NAME == 'osx' ]]; then brew update; fi
-  - if [[ $TRAVIS_OS_NAME == 'osx' ]]; then brew install yasm; fi
-
-script: |
-  if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
-    # Current Travis Ubuntu version uses libav which doesn't come with libswresample
-    cargo build --verbose --no-default-features --features "avcodec avfilter avformat avresample swscale" &&
-    cargo test  --verbose --no-default-features --features "avcodec avfilter avformat avresample swscale"
-  else
-    travis_wait cargo build --verbose --features "build"
-    cargo test  --verbose --features "build"
-  fi
-
-after_failure:
-  - find /usr -type f 2>/dev/null | grep -E 'lib(avcodec/version|avcodec/avcodec).h$' | xargs -I THEFILE -- sh -c 'echo "=== THEFILE ==="; cat THEFILE'

sys/.travis/install_linux.sh

@@ -1,17 +0,0 @@
-#!/bin/bash
-
-sudo apt-get update -q
-# From https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu
-sudo apt-get -y --force-yes install autoconf automake build-essential libass-dev libfreetype6-dev libsdl1.2-dev libtheora-dev libtool libva-dev libvdpau-dev libvorbis-dev libxcb1-dev libxcb-shm0-dev libxcb-xfixes0-dev pkg-config texinfo zlib1g-dev
-sudo apt-get install yasm
-pushd ~
-git clone https://github.com/FFmpeg/FFmpeg.git
-cd FFmpeg
-git checkout release/3.2
-mkdir ~/FFmpeg-build
-cd ~/FFmpeg-build
-../FFmpeg/configure --disable-ffprobe --disable-ffserver --disable-doc --enable-avresample
-make -j
-sudo make install
-make distclean
-popd

sys/shell.nix

@@ -1,21 +0,0 @@
-let
-  mozilla = import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz);
-in
-
-with (import <nixpkgs> {
-  overlays = [mozilla];
-});
-
-mkShell {
-  name = "ffmpeg-sys";
-
-  buildInputs = [
-    # For building.
-    clang rustChannels.stable.rust pkg-config ffmpeg_6
-  ];
-
-  RUST_BACKTRACE = 1;
-  RUSTFLAGS = "-C target-cpu=native";
-
-  LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
-}