feat: Real docker-based testing

This pull request switches testing to use an actual docker daemon, vs mocking everything out.

It may also catch actual breaking issues in our tests, which is great!

pre-delete

@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/config"
+source "$PLUGIN_BASE_PATH/common/functions"
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 
 PLUGIN_BASE_PATH="$PLUGIN_PATH"
@@ -10,7 +11,10 @@ source "$PLUGIN_BASE_PATH/common/functions"
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/functions"
 
 APP="$1"
-for SERVICE in "$PLUGIN_DATA_ROOT"/*; do
+pushd "$PLUGIN_DATA_ROOT" > /dev/null
+for SERVICE in *; do
+  dokku_log_verbose_quiet "Unlinking from $SERVICE"
   remove_from_links_file "$(basename "$SERVICE")" "$APP"
 done
+popd >/dev/null 2>&1 || pushd "/tmp" >/dev/null
 exit 0