Update setup script and requirements list.

setup.py

@@ -2,9 +2,10 @@
 
 from distutils.core import setup
 
+from pip.req import parse_requirements
 from setuptools import PackageFinder
 
-from aiogram import VERSION
+from aiogram import Stage, VERSION
 
 
 def get_description():
@@ -14,7 +15,7 @@ def get_description():
     :return: description
     :rtype: str
     """
-    with open('README.rst', encoding='utf-8') as f:
+    with open('README.rst', 'r', encoding='utf-8') as f:
         return f.read()
 
 
@@ -25,17 +26,16 @@ def get_requirements():
     :return: requirements
     :rtype: list
     """
-    requirements = []
-    with open('requirements.txt', 'r') as file:
-        for line in file.readlines():
-            line = line.strip()
-            if not line or line.startswith('#'):
-                continue
-            requirements.append(line)
+    filename = 'requirements.txt'
+    if VERSION.stage == Stage.DEV:
+        filename = 'dev_' + filename
 
-    return requirements
+    install_reqs = parse_requirements(filename, session='hack')
+    return [str(ir.req) for ir in install_reqs]
 
 
+install_requires = get_requirements()
+
 setup(
     name='aiogram',
     version=VERSION.version,
@@ -48,11 +48,13 @@ setup(
     long_description=get_description(),
     classifiers=[
         VERSION.pypi_development_status,  # Automated change classifier by build stage
-        'Programming Language :: Python :: 3.6',
         'Environment :: Console',
         'Framework :: AsyncIO',
-        'Topic :: Software Development :: Libraries :: Application Frameworks',
+        'Intended Audience :: Developers',
+        'Intended Audience :: System Administrators',
         'License :: OSI Approved :: MIT License',
+        'Programming Language :: Python :: 3.6',
+        'Topic :: Software Development :: Libraries :: Application Frameworks',
     ],
-    install_requires=get_requirements()
+    install_requires=install_requires
 )