Remove docker-compose verification during extension

docker-compose file verification shouldn't occur during the extension step since
the docker-compose files are meant to resolve in the context of the dock
container (e.g. env vars are set within and only within the dock container) so it
doesn't really make sense to do it before the dock container is even created.

bin/dock

@@ -477,10 +477,6 @@ extend_container() {
   fi
 
   notice "Extending Dock: $1..."
-  # Ensure project contains a valid docker-compose.yml
-  if ! is_valid_docker_compose $default_compose_file; then
-    return 1
-  fi
 
   # set image and container names accordingly
   container_name "$(convert_to_valid_container_name $1)"

test/options/extend.bats

@@ -14,24 +14,6 @@ teardown() {
   cd "${original_dir}"
 }
 
-@test "extending a Dock container with no docker-compose file at project root" { 
-  run dock -e test
-
-  [ "$status" -eq 1 ]
-  [[ "$output" =~ "does NOT exist!" ]]
-}
-
-@test "extending a Dock container with an invalid docker-compose schema" {
-  file docker-compose.yml <<-EOF
-version: 2 # version should be a string, not a numeral
-EOF
-
-  run dock -e test
-
-  [ "$status" -eq 1 ]
-  [[ "$output" =~ "Invalid docker-compose schema detected!" ]]
-}
-
 @test "configuration labels are added to Dock container during extension" {
   file Dockerfile <<-EOF
 FROM alpine:latest