Add the pip requirements for this venv.

automation/services/dhcp_api_requirements.txt

@@ -0,0 +1,16 @@
+certifi==2019.11.28
+chardet==3.0.4
+Click==7.0
+Flask==1.1.1
+gevent==1.4.0
+greenlet==0.4.15
+idna==2.8
+itsdangerous==1.1.0
+Jinja2==2.10.3
+MarkupSafe==1.1.1
+marshmallow==3.3.0
+requests==2.22.0
+urllib3==1.25.8
+webargs==5.5.2
+Werkzeug==0.16.0
+WSGIserver==1.3