chore(requirements): update psycopg2 version to 2.7.4
Fixes
+t+https://github.com/jek/blinker#egg=blinker
cffi==1.10.0
cookies==2.2.1
dnspython==1.15.0
+future==0.16.0
hrt==0.1.0
-jsonschema==2.6.0
# Here till they upload a Python3 compatible version of the library
-e git+https://github.com/google/ipaddr-py#egg=ipaddr
+jsonschema==2.6.0
Markdown==2.6.9
pexpect==4.2.1
psutil==5.3.1
-psycopg2==2.7.1
+psycopg2==2.7.4
PTP==0.4.2
pycurl==7.43.0
pyOpenSSL==17.2.0
PyVirtualDisplay==0.2.1
+pyyaml==3.12.0
requests==2.18.4
-six==1.10.0
selenium==3.4.3
+six==1.10.0
SQLAlchemy==1.1.13
tornado==5.0.1
-pyyaml==3.12.0
-future==0.16.0
--e git+https://github.com/jek/blinker#egg=blinker
+
