Changes to handling of log directory

[alexhernandezgarcia]

Summary of changes

• Removal of quick fix about race conditions: before, a random directory was created for each run. Now, by default, the directory created by Hydra with the date and time in the name contains the microseconds, which would prevent the potential issues with race conditions.
• A few default configurations have been changed:
  • TB loss instead of FM (because FM does not work for cont. environments)
  • Uniform proxy by default (because it works for all environments)
  • Hydra will not change directory by default.
• I have remove "alex" as the default user in the experiment config files and removed "debug" from the logdir path.

[michalkoziarski]

I believe this should be fine, but because you added SLURM_ID to the log dir; I am not totally sure if microseconds alone would be enough (no idea how precise Slurm is in starting jobs).

Added two discussion-type comments and one question that I think is important (on whether this works fine locally).

[alexhernandezgarcia]

@michalkoziarski approved?