design the uniform standard for device configuration

[Andrey1994]

Currently arguments for config_board method are device specific and determined by device manufactorer. For some devices we've added custom commands like: board.config_board("sampling_rate:500") but it's also not unified.

Need to take a look at all these commands and design uniform format for it in user API. Behind the scene these format will be converted to device-specific commands.

Types of commands we currently have:

• Muse boards preset commands (p50, p61,etc)
• OpenBCI Cyton (x12345678X)
• Ant Neuro (sampling_rate:500)