DEPENDS_ON arrows and text bold

[Leahh02]

Made the depends on arrows and text bold to address part of Issue 921. I also realized that when I set the output label to "value" the cat-grep-tar dag was messed up, so I set the label back to "glob". I ran the generate_graph.py file on my personal laptop, so I also want to try running it on Darwin to make sure it's still fine.

[pagrubel]

Leah, can you make the line a little thicker?

[pagrubel]

@Leahh02 In addition to making the lines a little thicker for DEPENDS_ON, could you add RESTARTED_FROM.

Here is an example of a checkpointed workflow.

[pagrubel]

@Leahh02 Just noticed this output from beeflow dag --help:

   Usage: beeflow dag [OPTIONS] WF_ID

  Export a DAG of the workflow to a GraphML file.

should it be png image file

[pagrubel]

Thanks Leah this look great!
The help verbage will be addressed in the other dag PR