Update self hosting scripts (#367)

split setup.env with example and base

add setup.env to .gitignore to avoid overwrite from new versions

Added test workflow for docker-compose 
and validated configure.sh generated variables

infrastructure_files/configure.sh

@@ -1,10 +1,32 @@
 #!/bin/bash
 
 source setup.env
+source base.setup.env
+
+if ! which envsubst > /dev/null 2>&1
+then
+  echo "envsubst is needed to run this script"
+  if [[ $(uname) == "Darwin" ]]
+  then
+    echo "you can install it with homebrew (https://brew.sh):"
+    echo "brew install gettext"
+  else
+    if which apt-get > /dev/null 2>&1
+    then
+      echo "you can install it by running"
+      echo "apt-get update && apt-get install gettext-base"
+    else
+      echo "you can install it by installing the package gettext with your package manager"
+    fi
+  fi
+  exit 1
+fi
 
 if [[ "x-$NETBIRD_DOMAIN" == "x-" ]]
 then
   echo NETBIRD_DOMAIN is not set, please update your setup.env file
+  echo If you are migrating from old versions, you migh need to update your variables prefixes from
+  echo WIRETRUSTEE_.. TO NETBIRD_
   exit 1
 fi