Update cli.py to use echo_always() for method output_raw and output_dot (#2244)

* replace `echo()` with `echo_always()` in method `output_raw` and `output_dot` to address error:
```
NameError: name 'echo' is not defined
```

Author: xujiboy

metaflow/cli.py

@@ -206,15 +206,15 @@ def output_raw(obj, json):
     else:
         _graph = str(obj.graph)
         _msg = "Internal representation of the flow:"
-    echo(_msg, fg="magenta", bold=False)
+    echo_always(_msg, fg="magenta", bold=False)
     echo_always(_graph, err=False)
 
 
 @cli.command(help="Visualize the flow with Graphviz.")
 @click.pass_obj
 def output_dot(obj):
-    echo("Visualizing the flow as a GraphViz graph", fg="magenta", bold=False)
-    echo(
+    echo_always("Visualizing the flow as a GraphViz graph", fg="magenta", bold=False)
+    echo_always(
         "Try piping the output to 'dot -Tpng -o graph.png' to produce "
         "an actual image.",
         indent=True,