Set Python requirements in lower case

Author: mdmintz

requirements.txt

@@ -9,7 +9,7 @@ pytest-xdist==1.22.2
 six==1.10.0
 flake8==3.5.0
 requests==2.18.4
-BeautifulSoup4==4.6.0
+beautifulsoup4==4.6.0
 unittest2==1.1.0
 chardet==3.0.4
 boto==2.48.0

setup.py

@@ -28,7 +28,7 @@
         'six==1.10.0',
         'flake8==3.5.0',
         'requests==2.18.4',
-        'BeautifulSoup4==4.6.0',
+        'beautifulsoup4==4.6.0',
         'unittest2==1.1.0',
         'chardet==3.0.4',
         'boto==2.48.0',