Manually Encode DAG for bnlearn

[rbartelme]

• [x] Draft graph(s) with pen/paper
• [x] Hard code directed acyclic graph with bnlearn
• [x] Check with @dlebauer to make sure graph edges fit known biology

[rbartelme]

Possible Encodings to simplify graph structure:

• Row+Col in plot = unique position
  • linked to physical parameters like soil type, measurements of a particular cultivar, etc.
• Translate VCF SNP's into character encodings
  • could be informed by @kshefchek's GWAS results??

[rbartelme]

Added a separate block of code for manual DAG generation, and another for learned structures

[rbartelme]

Manually encoded DAG in code