combine_plot_and_tree: Method for combining two ggplots
In jfukuyama/treeDA: Tree-Based Discriminant Analysis

This method takes a ggplot of some data along the tips of the tree and a ggplot of a tree and combines them. It assumes that you are putting the tree on top and that the x axis for the plot has the leaves in the correct position (this can be found using the function get_leaf_position).

1	combine_plot_and_tree(plot, tree.plot, tree.height = 5, print = TRUE)

`plot`	A plot of data about the leaves with the x axis corresponding to leaves.
`tree.plot`	A plot of the tree.
`tree.height`	The relative amount of space in the plot the tree should take up.
`print`	If true, the function will print the combined plot to a graphics device, otherwise it will just return the gtable object without printing.