Scheduled weekly dependency update for week 22 (#188)

* Update flask-caching from 1.7.1 to 1.7.2

* Update sqlalchemy from 1.3.3 to 1.3.4

* Update apache-libcloud from 2.4.0 to 2.5.0

* Update environs from 4.1.3 to 4.2.0

requirements.txt

@@ -1,22 +1,22 @@
 Babel==2.7.0
 Flask-BabelEx==0.9.3
-Flask-Caching==1.7.1
+Flask-Caching==1.7.2
 Flask-Migrate==2.5.2
 Flask-SQLAlchemy==2.4.0
 Flask-Script==2.0.6
 Flask-Security==3.0.0
 Flask-Testing==0.7.1
 Flask-WTF==0.14.2
 Flask==1.0.3
-SQLAlchemy==1.3.3
+SQLAlchemy==1.3.4
 WTForms==2.2.1
 Werkzeug==0.15.4
-apache-libcloud==2.4.0
+apache-libcloud==2.5.0
 bcrypt==3.1.6
 beautifulsoup4==4.7.1
 cached-property==1.5.1
 celery[sqlalchemy]==4.3.0
-environs==4.1.3
+environs==4.2.0
 gunicorn==19.9.0
 mkwvconf==0.1.1
 passlib==1.7.1