Changed from PyQt5 to PySide2

Changed GUI library to PySide2 from PyQt5 for MIT compliance. Closes #89 (closed)

b_asic/GUI/arrow.py

-from PyQt5.QtWidgets import QApplication, QWidget, QMainWindow, QLabel, QAction,\
+from PySide2.QtWidgets import QApplication, QWidget, QMainWindow, QLabel, QAction,\
 QStatusBar, QMenuBar, QLineEdit, QPushButton, QSlider, QScrollArea, QVBoxLayout,\
 QHBoxLayout, QDockWidget, QToolBar, QMenu, QLayout, QSizePolicy, QListWidget, QListWidgetItem,\
 QGraphicsLineItem, QGraphicsWidget
-from PyQt5.QtCore import Qt, QSize, QLineF, QPoint, QRectF
-from PyQt5.QtGui import QIcon, QFont, QPainter, QPen
+from PySide2.QtCore import Qt, QSize, QLineF, QPoint, QRectF
+from PySide2.QtGui import QIcon, QFont, QPainter, QPen
 
 
 class Arrow(QGraphicsLineItem):