Create IV_graph.ipynb

Here is the code for the IV curve plotting, the structure was based off of what you showed Nick and I.

I used the data from last Wednesday when Nick and I recorded solar currents w/ resistors. There was some cloud coverage that affected the numbers, but I wanted to use this as practice for graphing an IV curve with more realistic numbers. 

The link for the visual view of the graph is found within the README.md that is accompanied with this file