Install Sentry SDK with other dependencies

Previously I was using Salt to install the Sentry SDK (previously known
as "raven") only on the production server, but that's not really
necessary. This will just install it everywhere, and then we'll only
actually integrate it in production.

salt/salt/raven.sls

@@ -1,6 +0,0 @@
-{% from 'common.jinja2' import app_dir, venv_dir %}
-
-raven-pip-install:
-  pip.installed:
-    - name: raven
-    - bin_env: {{ venv_dir }}

salt/salt/top.sls

@@ -30,7 +30,6 @@ base:
   'prod':
     - nginx.shortener-config
     - nginx.static-sites-config
-    - raven
     - prod-config
   'monitoring':
     - nginx

tildes/requirements-to-freeze.txt

@@ -30,6 +30,7 @@ pytest
 pytest-mock
 PyYAML  # needs to be installed separately for webassets
 qrcode
+sentry-sdk
 SQLAlchemy
 SQLAlchemy-Utils
 stripe

tildes/requirements.txt

@@ -80,6 +80,7 @@ redis==3.0.1
 repoze.lru==0.7
 requests==2.21.0
 requirements-detector==0.6
+sentry-sdk==0.6.6
 setoptconf==0.2.0
 simplejson==3.16.0
 six==1.12.0