rotate.somites: Function for rotating the somites
In erinboyleanderson/CellTrackingEBA: Cell tracking calculations

This function rotates the somites so they are aligned correctly. This is important for labelling the cells with the somite identity later

1	rotate.somites(somiteDF, bros, side)

`somiteDF`	Dataframe containing the boundary information. must include the following column names: Embryo, X, Y, boundary. Embryo is the number of the embryo, Boundary is the somite boundary, must be in the form 0-1, 1-2, etc where the numbers represent the somites that are being bound (ie 0-1 is the boundary between somite 0 and somite 1) ALSO MUST INCLUDE minimally boundary 0-1 and 5-6!
`bros`	number of embryos in the dataframe
`side`	dataframe consisting of the number of the embryo, the side (L vs R) and a multiplier (-1 or 1) based on if the embryo is on the L or R side