[WIP] Feature update interval

[vgonisanz]

[WIP] = Work in progress.

Hi. I create a pull request to discuss about add this new feature to pycoinmon.

• Moved parse arguments to init function. ✔️
• Refactor methods needed to avoid repeat code lines with new code. ✔️
• Added argument to refresh each x second data provided by CoinMarketCap ✔️

Need to clear how:

• Stop the refresh bucle with a valid crossplatform method. ✔️
• Update data without reprint everytime, in example, using os.system('cls') # on windows or os.system('clear') # on linux / os x ✔️

This feature could be improved, so, comments are welcome.

[RDCH106]

Fixed Codacy error --> Restore missing find function

[RDCH106]

• To abort execution, without extra dependencies, require a kill signal (control + C) ✔️

[vgonisanz]

Awesome. I think that the features is completed!