BTHLABS-64: Support for customized environments

Co-authored-by: Tomek Wójcik <labs@tomekwojcik.pl>
Co-committed-by: Tomek Wójcik <labs@tomekwojcik.pl>

tasks.py

@@ -146,6 +146,7 @@ def build(ctx: Context,
           image_tag=None,
           machine=None,
           platform=None,
+          registry='docker-hosted.nexus.bthlabs.pl',
           ):
     image_tag = image_tag or '{target}.{{short_sha}}'.format(target=target)
 
@@ -178,7 +179,7 @@ def build(ctx: Context,
                 if platform is not None
                 else ''
             ),
-            f'-t docker-hosted.nexus.bthlabs.pl/hotpocket/{service}:{docker_build_ctx.tag}',  # noqa: E501
+            f'-t {registry}/hotpocket/{service}:{docker_build_ctx.tag}',  # noqa: E501
             f'-f services/{service}/Dockerfile',
             f'--build-arg IMAGE_ID={image_tag}',
             f'--target {docker_build_ctx.target}',