Scheduled weekly dependency update for week 21 (#370)

* Update pyflakes from 1.6.0 to 2.0.0

* Update pyflakes from 1.6.0 to 2.0.0

* Update pytest from 3.5.1 to 3.6.0

* Update pytest from 3.5.1 to 3.6.0

* Update pytest from 3.5.1 to 3.6.0

* Update aiohttp-session from 2.3.0 to 2.5.1

* Update aiohttp from 3.1.3 to 3.2.1

* Update aiomysql from 0.0.14 to 0.0.15

* Update aiopg from 0.13.2 to 0.14.0

* Update motor from 1.2.1 to 1.2.2

* Update python-dateutil from 2.7.2 to 2.7.3

* Update pymysql from 0.8.0 to 0.8.1

Author: pyup.io bot

demos/blog/requirements-dev.txt

@@ -1,4 +1,4 @@
-pyflakes==1.6.0
+pyflakes==2.0.0
 pep8==1.7.1
-pytest==3.5.1
+pytest==3.6.0
 ipdb==0.11

demos/blog_react/requirements-dev.txt

@@ -1,4 +1,4 @@
-pyflakes==1.6.0
+pyflakes==2.0.0
 pep8==1.7.1
-pytest==3.5.1
+pytest==3.6.0
 ipdb==0.11

requirements-dev.txt

@@ -1,19 +1,19 @@
 aiohttp-jinja2==1.0.0
 aiohttp-security==0.2.0
-aiohttp-session==2.3.0
-aiohttp==3.1.3
-aiomysql==0.0.14
-aiopg==0.13.2
+aiohttp-session==2.5.1
+aiohttp==3.2.1
+aiomysql==0.0.15
+aiopg==0.14.0
 coverage==4.5.1
 docker==3.3.0
 flake8==3.5.0
 ipdb==0.11
-motor==1.2.1
+motor==1.2.2
 pytest-cov==2.5.1
 pytest-sugar==0.9.1
-pytest==3.5.1
-python-dateutil==2.7.2
+pytest==3.6.0
+python-dateutil==2.7.3
 sqlalchemy==1.2.7
 trafaret==2.0.0a1
-pymysql==0.8.0
+pymysql==0.8.1
 -r requirements-doc.txt