feat: switch to pypy

Python 2.7 reached End Of Life as of Jan 01, 2020. Pypy has stated that
they will continue to support Python 2.7 for the forseeable future. As
a stop-gap for this package, we should switch to Pypy.

Closes mozilla-services/services-engineering#22

Makefile

@@ -17,6 +17,10 @@ INSTALL = ARCHFLAGS=$(ARCHFLAGS) CFLAGS=$(CFLAGS) $(VENV)/bin/pip install
 .PHONY: all install install-dev virtualenv tests
 
 help:
+	@echo "Since Python 2.7 is no longer supported, but is used by this project,"
+	@echo "please be sure to install pypy 2.7 <http://pypy.org/download.html> and"
+	@echo "the system appropriate `pypy-dev` package"
+	@echo ""
 	@echo "Please use 'make <target>' where <target> is one of"
 	@echo "  install                     install dependencies and prepare environment"
 	@echo "  install-dev                 install dependencies and everything needed to run tests"
@@ -43,7 +47,7 @@ $(DEV_STAMP): $(PYTHON) dev-requirements.txt
 
 virtualenv: $(PYTHON)
 $(PYTHON):
-	$(VIRTUALENV) $(VENV)
+	$(VIRTUALENV) -p pypy $(VENV)
 
 build-requirements:
 	$(VIRTUALENV) $(TEMPDIR)

requirements.txt

@@ -8,6 +8,7 @@ configparser==3.7.4
 cornice==3.5.1
 cryptography==2.6.1
 enum34==1.1.6
+gunicorn==19.10.0
 hawkauthlib==2.0.0
 hupper==1.6.1
 idna==2.8
@@ -16,6 +17,7 @@ konfig==1.1
 Mako==1.0.9
 MarkupSafe==1.1.1
 mozsvc==0.10
+mysqlclient==1.4.6
 Paste==3.0.8
 PasteDeploy==2.0.1
 plaster==1.0