Add PyYAML as a required package

base_requirements.txt

@@ -83,6 +83,10 @@ py-gfm
 # https://github.com/Legrandin/pycryptodome
 pycryptodome
 
+# YAML rendering library
+# https://github.com/yaml/pyyaml
+PyYAML
+
 # In-memory key/value store used for caching and queuing
 # https://github.com/andymccurdy/redis-py
 redis

requirements.txt

@@ -19,5 +19,6 @@ Pillow==7.0.0
 psycopg2-binary==2.8.4
 py-gfm==0.1.4
 pycryptodome==3.9.4
+PyYAML==5.3
 redis==3.3.11
 svgwrite==1.3.1