Update dependencies

Couldn't update requests to 2.21.0 due to an urllib3 incompatibility.

requirements.txt

@@ -1,58 +1,58 @@
-alembic==1.0.6
-amqp==2.4.0
-attrs==18.2.0
+alembic==1.0.9
+amqp==2.4.2
+attrs==19.1.0
 Babel==2.6.0
-billiard==3.5.0.5
+billiard==3.6.0.0
 blinker==1.4
-celery==4.2.1
-certifi==2018.11.29
+celery==4.3.0
+certifi==2019.3.9
 chardet==3.0.4
 click==7.0
 click-log==0.3.2
 enum34==1.1.6 ; python_version<'3.4'
 Flask==1.0.2
 Flask-Alembic==2.0.1
-flask-allows==0.7.1
+flask-allows==0.6.0
 Flask-BabelPlus==2.1.1
-Flask-Caching==1.4.0
+Flask-Caching==1.7.1
 Flask-DebugToolbar==0.10.1
 flask-debugtoolbar-warnings==0.1.0
 Flask-Limiter==1.0.1
 Flask-Login==0.4.1
 Flask-Mail==0.9.1
 Flask-Redis==0.3.0
-Flask-SQLAlchemy==2.3.2
+Flask-SQLAlchemy==2.4.0
 Flask-Themes2==0.1.4
 flask-whooshee==0.6.0
 Flask-WTF==0.14.2
-flaskbb-plugin-conversations==1.0.4
-flaskbb-plugin-portal==1.1.2
-idna==2.8
+flaskbb-plugin-conversations==1.0.6
+flaskbb-plugin-portal==1.1.3
+idna==2.7
 itsdangerous==1.1.0
-Jinja2==2.10
-kombu==4.2.2.post1
+Jinja2==2.10.1
+kombu==4.5.0
 limits==1.3
-Mako==1.0.7
-MarkupSafe==1.1.0
+Mako==1.0.9
+MarkupSafe==1.1.1
 mistune==0.8.4
 olefile==0.46
-Pillow==5.4.1
-pluggy==0.8.1
+Pillow==6.0.0
+pluggy==0.9.0
 Pygments==2.3.1
-python-dateutil==2.7.5
-python-editor==1.0.3
-pytz==2018.9
-redis==3.0.1
-requests==2.21.0
+python-dateutil==2.8.0
+python-editor==1.0.4
+pytz==2019.1
+redis==3.2.1
+requests==2.20.0
 simplejson==3.16.0
 six==1.12.0
 speaklater==1.3
-SQLAlchemy==1.2.16
+SQLAlchemy==1.3.3
 SQLAlchemy-Utils==0.33.11
 Unidecode==1.0.23
 urllib3==1.24.1
-vine==1.2.0
-Werkzeug==0.14.1
+vine==1.3.0
+Werkzeug==0.15.2
 Whoosh==2.7.4
 WTForms==2.2.1
 -e .