Update requirements.

Author: Uman Shahzad

requirements.txt

@@ -4,21 +4,21 @@
 #
 #    pip-compile --no-index --output-file requirements.txt requirements.in
 #
-atomicwrites==1.2.1       # via pytest
-attrs==18.2.0             # via pytest
+atomicwrites==1.3.0       # via pytest
+attrs==19.1.0             # via pytest
 cachetools==2.1.0
-certifi==2018.10.15       # via requests
+certifi==2019.3.9         # via requests
 chardet==3.0.4            # via requests
 click==7.0                # via pip-tools
-idna==2.7                 # via requests
-more-itertools==4.3.0     # via pytest
+idna==2.8                 # via requests
+more-itertools==6.0.0     # via pytest
 pip-tools==3.1.0
-pluggy==0.7.1             # via pytest
-py==1.7.0                 # via pytest
+pluggy==0.9.0             # via pytest
+py==1.8.0                 # via pytest
 pycodestyle==2.4.0
 pytest==3.8.2
 python-dateutil==2.6.1
 pytz==2017.2
-requests==2.19.1
-six==1.11.0               # via more-itertools, pip-tools, pytest, python-dateutil
-urllib3==1.23             # via requests
+requests==2.21.0
+six==1.12.0               # via pip-tools, pytest, python-dateutil
+urllib3==1.24.1           # via requests