Added pre-commit as a dependency.

.pre-commit-config.yaml

+repos:
+  -   repo: git://github.com/guykisel/prospector-mirror
+    sha: ''  # Use the sha / tag you want to point at
+    hooks:
+    -   id: prospector

backend/requirements.txt

@@ -9,3 +9,4 @@ xlrd~=1.0.0
 pytest-cov~=2.5.1
 prospector~=0.12.7
 django-cors-headers~=2.1.0
+pre-commit~=1.4.1
\ No newline at end of file