Bug Fix for Physical Members & Change to Default Dependencies

• Fixed physical member load and deflection diagrams. Physical members are a newer feature. Member internal results were being reported correctly, but the diagrams for these members had not been revised to plot correctly. The old method for plain members was still being used. Physical members were not considering that a physical member was made from multiple submembers, and results for each span needed to be combined to get the whole plot.
• Switched some commonly used python libraries to be installed by default with Pynite. Most Pynite users will want these libraries installed for full-featured use of Pynite. These libraries help with Pynite visualizations, plotting, the sparse solver, and Jupyter Lab functionality. This is just easier for new python users. I was getting a lot of questions about how to set up libraries, and this takes the guesswork away. This is part of Pynite's objective to stay easy to use. I figure advanced python users can uninstall the libraries they don't want, rather than making newbie users install the ones they want.