process_solution() does not process folder in the format *Solution (1).zip

[claytonpbarrows]

If 2 or more same-name PLEXOS simulations are running at the same time, the log files and associated solution files will get a numbered ending in parentheses corresponding to the order in which they are run. This causes rPLEXOS to fail to recognize the zip file as a PLEXOS solution file. I'll add more documentation when I can.

[claytonpbarrows]

> db = './OutputFiles/Model DA Base BR50 Solution/Model DA Base BR50 Solution (1).zip'
> library(rplexos)
> process_solution(db)
Warning: ./OutputFiles/Model DA Base BR50 Solution/Model DA Base BR50 Solution (1).zip is not a PLEXOS solution file and was ignored.

[danielsjf]

This is due to the fix for #52. The regex was too constraining. I will fix this.

[danielsjf]

@claytonpbarrows I've tried to fix the issue. Could you try if it works on your solutions? By the way, the new rplexos version does not compile on Linux (#60). Did you see similar issues with the previous builds? If not, do you maybe have a Linux version available to investigate this?