Added requirement numpy >= 1.20

setup.py

@@ -9,7 +9,11 @@ setup(name="pulse_lib",
 	version="1.5.6",
 	packages = find_packages(),
     python_requires=">=3.7",
-    install_requires=['si_prefix', 'qcodes>=0.27.0'],
+    install_requires=[
+            'si_prefix',
+            'qcodes>=0.27.0',
+            'numpy>=1.20.0',
+            ],
     license='MIT',
 	)