Add cpu and ram upper limits for user's containers

[kunalvirwal]

Currently by default 0.25 cpus and 0.5 GB ram is allotted to user's app container by default and these values are modifiable by the user.
We need to add an upper limit for user's containers that can be added in the config.toml which will limit the cpu and ram limits per container.

Note

These limits must not apply to the admin and the admin should have the power to increase the user's container specs to above the rate limit.