Fix issues with @Environment (#452)

* Fix issues with @Environment

context https://gitter.im/metaflow_org/community?at=604a2bfb44f5a454a46cc7f8

* add more comments

* roll back to previous commit

Author: savingoyal

metaflow/metadata/metadata.py

@@ -495,5 +495,5 @@ def __init__(self, environment, flow, event_logger, monitor):
         self._monitor = monitor
         self._environment = environment
         self._runtime = os.environ.get(
-            'METAFLOW_MLI_RUNTIME_NAME', 'dev')
+            'METAFLOW_RUNTIME_NAME', 'dev')
         self.add_sticky_tags(sys_tags=self._tags())

metaflow/plugins/environment_decorator.py

@@ -9,7 +9,7 @@ class EnvironmentDecorator(StepDecorator):
     Step decorator to add or update environment variables prior to the execution of your step.
 
     The environment variables set with this decorator will be present during the execution of the
-    step both locally or on Batch.
+    step.
 
     To use, annotate your step as follows:
     ```
@@ -27,5 +27,5 @@ def myStep(self):
     name = 'environment'
     defaults = {'vars': {}}
 
-    def step_init(self, flow, graph, step, decos, environment, datastore, logger):
-        os.environ.update(self.attributes['vars'].items())
+    def runtime_step_cli(self, cli_args, retry_count, max_user_code_retries):
+        cli_args.env.update(self.attributes['vars'].items())