Implement load balancer

[SamuelWei]

Is your feature request related to a problem? Please describe.
The system should use a load balancer for creating new meetings and display server status.
Similar to https://github.com/blindsidenetworks/scalelite

Describe the solution you'd like
Use data collected by #64 for each new meeting to calculate the server load based on amount of meetings and estimated network traffic, cpu usage, etc. and use a server specific multiplicator to handle different hardware.

Use the server with the lowest load of the server pool (#30) the room has selected and try to create meeting. If not possible, try next less loaded server. If all servers are not available throw error.

Describe alternatives you've considered
Just use https://github.com/blindsidenetworks/scalelite

[dsst95]

@SamuelWei isn't this already implemented in the RoomController?

[SamuelWei]

Yes, it was implemented with #88