fix: Closes issue #8 (read body)

OVH and other providers remove the contents of /etc/issue in their
OS templates. So we need to ask the user manually to tell us what the
OS is as a Fallback.

In addition we removed the `OsSupported.php` Installer Policy because
its not really needed. We have already determined that the user has a
supported OS.

install.sh

@@ -1,15 +1,59 @@
 #!/usr/bin/env bash
 
+source tools/colors.sh
+
 # Detect OS
 case $(head -n1 /etc/issue | cut -f 1 -d ' ') in
     Debian)     type="debian" ;;
     Ubuntu)     type="ubuntu" ;;
-    *)          type="rhel" ;;
+    *)          type='' ;;
 esac
 
-# Fallback to Ubuntu
-if [ ! -e "/etc/redhat-release" ]; then
-    type='ubuntu'
+# Unable to detect OS Properly
+# Note: OVH and other providers remove the contents of /etc/issue in their OS templates
+#   so we need to ask the user manually to tell us what the OS is as a Fallback
+# Ref: https://github.com/ServNX/UNIT3D-INSTALLER/issues/8
+if [ "$type" = '' ]; then
+    echo -e "\n$Red We was unable to automatically determine your OS! $Color_Off"
+    echo -e "\n$Purple This can happen if you are using an OS template from a provider like OVH amongst others. $Color_Off\n"
+
+    PS3='Please select the # for your OS: '
+    options=("Ubuntu 18.04" "Ubuntu 16.04" "Other Ubuntu" "Debian" "Other" "Quit")
+    select opt in "${options[@]}"
+    do
+        case $opt in
+            "Ubuntu 18.04")
+                echo 'Ubuntu 18.04 LTS \n \l' > /etc/issue
+                type='ubuntu'
+                break
+                ;;
+            "Ubuntu 16.04")
+                echo 'Ubuntu 16.04 LTS \n \l' > /etc/issue
+                type='ubuntu'
+                break
+                ;;
+            "Other Ubuntu")
+                echo 'Ubuntu UNKNOWN LTS \n \l' > /etc/issue
+                type='ubuntu'
+                break
+                ;;
+            "Debian")
+                echo 'Debian GNU/Linux \n \l' > /etc/issue
+                type='debian'
+                break
+                ;;
+            "Other")
+                echo -e "$Red Unsupported GNU/Linux distribution $Color_Off"
+                exit 1
+                ;;
+            "Quit")
+                exit 0
+                ;;
+            *)
+                echo -e "$Red Invalid Option $REPLY $Color_Off"
+                ;;
+        esac
+    done
 fi
 
 if [ -e $type.sh ]; then

src/Installer/Policies/InstallerPolicies.php

@@ -5,11 +5,6 @@
 class InstallerPolicies extends BasePolicy
 {
     private $steps = [
-        /*
-         * Os and Distribution Support policies
-         */
-        OsSupported::class,
-
         /*
          * Configuration policies
          */