Add dnadiff distance matrix generator. Including tests and test data.
Fix test not removing temp dir. Fix taking M-to-M AvgIdentity instead of 1-to-1.
Add hierarchical clustering + test and options to skip dnadiff or matrix calculation.
Add dir_utils to CONCOCT module
Add seaborn and mummer to travis
Add multiprocessing
Remove old utils script from scripts dir
Add xvfb to set DISPLAY variable in Travis
Add fasta names to fasta file tsv file to output folder. Add more documentation.
Set backend to Agg within plotting function to make plotting work on Uppmax. Fix writing of fasta names in main.
Increase size of cluster plot in case of many samples
Add dendrogram plot and 88 bin test.

With a large amount of samples the clustering becomes hard to see on the
heatmap so it is nice to have a separate dendrogram plot.
Use basename of fasta files for fasta names in case no fasta names are given.
Add dnadiff check, change test folders, fix CmdException

The dependencies for dnadiff are checked verbosely.

Tests for scripts are now in a different folder

The bug for multiprocessing with custom Exceptions is handled now by converting
the CmdException to a regular Exception.
Merge pull request #121 from inodb/dist_matrix_script

Add distance matrix script that uses MUMmer to compute distance between bins (fasta files)