SLiM-Tree Paper

[ebrintn]

Revisiting SLiM-Tree for publication - list of things that need to happen:

• Update to SLiM 4
• Implement proper counting of dN/dS
• Revisit user guide
• Merge dev with master
• Revisit paper
• Update readme
• DN/DS example

[ebrintn]

@afarineshp @jasondk please add as needed

[ebrintn]

Just need to add @afarineshp changes

[ebrintn]

dn/ds example is in progress - just taking a while because it kept on timing out on me :( I've updated the amount of time to run for