Replace references to Pyside2 with qtpy

Author: jcornall

eqt/ui/UISliderWidget.py

@@ -1,5 +1,5 @@
-from PySide2 import QtCore, QtGui
-from PySide2.QtWidgets import QApplication, QGridLayout, QLabel, QLineEdit, QSlider, QWidget
+from qtpy import QtCore, QtGui
+from qtpy.QtWidgets import QApplication, QGridLayout, QLabel, QLineEdit, QSlider, QWidget
 
 
 class UISliderWidget(QWidget):

test/test_UISliderWidget.py

@@ -1,8 +1,8 @@
 import unittest
 
 from parameterized import parameterized
-from PySide2 import QtGui
-from PySide2.QtWidgets import QGridLayout, QLabel, QLineEdit, QSlider
+from qtpy import QtGui
+from qtpy.QtWidgets import QGridLayout, QLabel, QLineEdit, QSlider
 
 from eqt.ui import UISliderWidget