Significance levels for output

[brennonbrimhall]

Let the user define a minimum threshold for the generated tree.

For example, if the probability tree is like this (taken from a 2018nytr output):

Rank 1: 2791 @ 100%
        Rank 2: 3117 @ 32.49%
                Rank 3: 3044 @ 19.63%
                        Rank 4: 6621 @ 33.9%
                                Rank 5: 333 @ 32.33%
                                        Rank 6: 3996 @ 49.1%
                                                Rank 7: 3360 @ 36.44%
                                                        Rank 8: 20 @ 44.21%
                                                                Rank 9: 1493 @ 45.86%
                                                                        Rank 10: 3990 @ 57.89%
                                                                                Rank 11: 6484 @ 63.64%
                                                                                        Rank 12: 1860 @ 40.82%
                                                                                        Rank 12: 2013 @ 20.41%
                                                                                        Rank 12: 4508 @ 14.29%
                                                                                        Rank 12: 1665 @ 14.29%
                                                                                        Rank 12: 1156 @ 8.163%
                                                                                        Rank 12: 5123 @ 2.041%
                                                                                Rank 11: 1156 @ 31.17%
                                                                                        Rank 12: 6484 @ 95.83%
                                                                                        Rank 12: 1665 @ 4.167%
                                                                                Rank 11: 1860 @ 2.597%
                                                                                        Rank 12: 1156 @ 50%
                                                                                        Rank 12: 6300 @ 50%
                                                                                Rank 11: 4508 @ 2.597%
                                                                                        Rank 12: 6484 @ 50%
                                                                                        Rank 12: 1156 @ 50%
                                                                        Rank 10: 6484 @ 24.06%
                                                                                Rank 11: 3990 @ 68.75%
                                                                                        Rank 12: 2013 @ 50%
                                                                                        Rank 12: 1156 @ 22.73%
                                                                                        Rank 12: 1665 @ 22.73%
                                                                                        Rank 12: 1860 @ 4.545%

and the user has specified a threshold of .05, then we should only output this:

Rank 1: 2791 @ 100%
        Rank 2: 3117 @ 32.49%
                Rank 3: 3044 @ 19.63%
                        Rank 4: 6621 @ 33.9%
                                Rank 5: 333 @ 32.33%
                                        Rank 6: 3996 @ 49.1%
                                                Rank 7: 3360 @ 36.44%
                                                        Rank 8: 20 @ 44.21%
                                                                Rank 9: 1493 @ 45.86%
                                                                        Rank 10: 3990 @ 57.89%
                                                                                Rank 11: 6484 @ 63.64%
                                                                                        Rank 12: 1860 @ 40.82%
                                                                                        Rank 12: 2013 @ 20.41%
                                                                                        Rank 12: 4508 @ 14.29%
                                                                                        Rank 12: 1665 @ 14.29%
                                                                                        Rank 12: 1156 @ 8.163%
                                                                                Rank 11: 1156 @ 31.17%
                                                                                        Rank 12: 6484 @ 95.83%
                                                                        Rank 10: 6484 @ 24.06%
                                                                                Rank 11: 3990 @ 68.75%
                                                                                        Rank 12: 2013 @ 50%
                                                                                        Rank 12: 1156 @ 22.73%
                                                                                        Rank 12: 1665 @ 22.73%

[brennonbrimhall]

Current usage is augur <teams.csv> <matches.csv> <depth> [numMonteCarloSims]. I suggest we do augur <teams.csv> <matches.csv> <depth> <alpha> [numMonteCarloSims] for this (alpha is typically the symbol used for statistical significance). There may be a better way though.