Fixing hogwash issue when plotting very large dataset.
Used got the following error message:
```
[1] "Ancestral reconstruction complete: 2021-04-23 12:54:56"
[1] "Permutation test complete: 2021-04-23 14:39:56"
Error in do.call("cbind", lapply(x, "is.na")) :
variable names are limited to 10000 bytes
Calls: hogwash ... check_if_g_mat_can_be_plotted -> is.na -> is.na.data.frame -> do.call
Execution halted
```
Failed run details:
622552 variants
992 samples
pheno = pheno_test
geno = geno_test
tree = tree_new
tree_type = "phylogram"
file_name = "hogwash_both"
dir = "."
perm = 10000
fdr = 0.15
bootstrap = 0.70
test= "both"
Successful run had 458409 variants (only difference).
So why did larger run fail?
TODO:
* Generate random genotype matrix with 700,000 variants
* Generate random phenotype with 1,000 samples
* Run with stated settings and fix plotting.