drop Debian Stretch support

Fixes #1194

Vagrantfile

@@ -52,10 +52,6 @@ Vagrant.configure("2") do |config|
     os.vm.box = "bento/ubuntu-16.04"
     provision_libretime(os, "debian.sh", installer_args)
   end
-  config.vm.define "debian-stretch" do |os|
-    os.vm.box = "bento/debian-9"
-    provision_libretime(os, "debian.sh", installer_args)
-  end
   config.vm.define "debian-buster" do |os|
     os.vm.box = "bento/debian-10"
     provision_libretime(os, "debian.sh", installer_args)

docs/_docs/vagrant.md

@@ -91,13 +91,12 @@ directory.
 With the above instructions LibreTime is installed on Ubuntu Xenial Xerus. The Vagrant setup
 offers the option to choose a different operation system according to you needs.
 
-| OS           | Command                     | Comment                                                     |
+| OS           | Command                    | Comment                                                     |
-| ------------ | --------------------------- | ----------------------------------------------------------- |
+| ------------ | -------------------------- | ----------------------------------------------------------- |
-| Debian 10    | `vagrant up debian-buster`  | Install on Debian Buster.                                   |
+| Debian 10    | `vagrant up debian-buster` | Install on Debian Buster.                                   |
-| Debian 9     | `vagrant up debian-stretch` | Install on current Debian Stretch.                          |
+| Ubuntu 18.04 | `vagrant up ubuntu-bionic` | Install on Ubuntu Bionic Beaver.                            |
-| Ubuntu 18.04 | `vagrant up ubuntu-bionic`  | Install on current Ubuntu Bionic Beaver.                    |
+| Ubuntu 16.04 | `vagrant up ubuntu-xenial` | Install on Ubuntu Xenial Xerus.                             |
-| Ubuntu 16.04 | `vagrant up ubuntu-xenial`  | Install on Ubuntu Xenial Xerus.                             |
+| CentOS       | `vagrant up centos`        | CentOS 8 with native systemd support and activated SELinux. |
-| CentOS       | `vagrant up centos`         | CentOS 8 with native systemd support and activated SELinux. |
 
 ## Troubleshooting
 

install

@@ -623,7 +623,6 @@ fi
 # Validate the distribution and release is a supported one; set boolean flags.
 is_debian_dist=false
 is_debian_buster=false
-is_debian_stretch=false
 is_ubuntu_dist=false
 is_ubuntu_bionic=false
 is_ubuntu_xenial=false
@@ -652,9 +651,9 @@ case "${dist}-${code}" in
         exit 1
         ;;
     debian-9|debian-stretch)
-        code="stretch"
+        echo -e "ERROR: Debian Stretch is archived and does not receive any security or other updates since 2020-06-06." >&2
-        is_debian_dist=true
+        echo -e "The LibreTime installer dropped support for installing LibreTime on Stretch in 3.0.0-alpha.10." >&2
-        is_debian_stretch=true
+        exit 1
         ;;
     debian-10|debian-buster)
         code="buster"
@@ -663,11 +662,10 @@ case "${dist}-${code}" in
         ;;
     #Fix for Raspbian 9 (stretch)
     raspbian-9|9)
-	code="stretch"
+        echo -e "ERROR: Raspbian Stretch is archived and does not receive any security or other updates since 2020-06-06." >&2
-	dist="debian"
+        echo -e "The LibreTime installer dropped support for installing LibreTime on Stretch in 3.0.0-alpha.10." >&2
-	is_debian_dist=true
+        exit 1
-	is_debian_stretch=true
+        ;;
-	;;
     #End of fix
     #Fix for Raspbian 10 (buster)
     raspbian-10|10)
@@ -683,11 +681,6 @@ case "${dist}-${code}" in
         echo -e "The LibreTime installer dropped support for installing LibreTime on Jessie in 3.0.0-alpha.8." >&2
         exit 1
         ;;
-    debian-7|debian-wheezy)
-        echo -e "ERROR: Debian Wheezy is archived and does not receive any security or other updates since 2018-05-31." >&2
-        echo -e "The LibreTime installer dropped support for installing LibreTime on Wheezy in 3.0.0-alpha.6." >&2
-        exit 1
-        ;;
     centos-8)
         is_centos_dist=true
         is_centos_8=true
@@ -1083,7 +1076,7 @@ if $is_debian_buster; then
     loudCmd "a2enmod rewrite php7.3 proxy proxy_http"
 elif $is_ubuntu_bionic; then
     loudCmd "a2enmod rewrite php7.2 proxy proxy_http"
-elif $is_ubuntu_xenial || $is_debian_stretch; then
+elif $is_ubuntu_xenial; then
     loudCmd "a2enmod rewrite php7.0 proxy proxy_http"
 elif $is_centos_dist; then
     verbose "TODO: enable Apache modules mod_rewrite, mod_php, mod_proxy and mod_proxy_http manually"

installer/lib/requirements-debian-stretch.apt

@@ -1,59 +0,0 @@
-apache2
-coreutils
-curl
-ecasound
-flac
-git
-gstreamer1.0-plugins-bad
-gstreamer1.0-plugins-good
-gstreamer1.0-plugins-ugly
-icecast2
-lame
-libao-ocaml
-libapache2-mod-php7.0
-libcamomile-ocaml-data
-libfaad2
-libmad-ocaml
-libopus0
-libportaudio2
-libpulse0
-libpq-dev
-libsamplerate0
-libsoundtouch-ocaml
-libtaglib-ocaml
-libvo-aacenc0
-liquidsoap
-lsb-release
-lsb-release
-lsof
-mpg123
-patch
-php7.0
-php7.0-bcmath
-php7.0-curl
-php7.0-dev
-php7.0-gd
-php7.0-mbstring
-php7.0-pgsql
-php-amqplib
-php-apcu
-php-pear
-postgresql
-postgresql-client
-pwgen
-python3
-python3-gst-1.0
-python3-pika
-python3-pip
-python3-virtualenv
-python3-cairo
-rabbitmq-server
-systemd-sysv
-unzip
-uwsgi
-uwsgi-plugin-python3
-vorbisgain
-vorbis-tools
-vorbis-tools
-xmlstarlet
-zip