Update requirments and setup configuration

Author: RJMW

requirements.txt

@@ -8,4 +8,6 @@ Matplotlib<3.0.0
 seaborn<=0.9.0
 pyteomics<=3.5.1
 tqdm<=4.28.1
-biopython<=1.72
+biopython<=1.72
+pyqt5<=5.10 ; python_version >= '3.0'
+python-qt5<=0.3.0 ; python_version < '3.0' and sys_platform == 'win32'

setup.py

@@ -8,10 +8,7 @@
 
 def main():
 
-    if sys.platform == "win32" or sys.platform == "win64":
-        install_requires = open('requirements-win.txt').read().splitlines()
-    else:
-        install_requires = open('requirements.txt').read().splitlines()
+    install_requires = open('requirements.txt').read().splitlines()
 
     setuptools.setup(name="beams",
         version=beams.__version__,