3384 Unpin coverage

.gitignore

@@ -51,3 +51,9 @@ zope.interface-*.egg
 # This is the plaintext of the private environment needed for some CircleCI
 # operations.  It's never supposed to be checked in.
 secret-env-plain
+
+# coverage 5.x writes a series of sqlite files.
+/.coverage.*
+
+# ignore results of running integration tests.
+/integration.eliot.json

newsfragments/3384.minor

@@ -0,0 +1 @@
+Coverage is not pinned at ~= 4.5 anymore.

setup.py

@@ -377,7 +377,7 @@ def run(self):
               # coverage 5.0 breaks the integration tests in some opaque way.
               # This probably needs to be addressed in a more permanent way
               # eventually...
-              "coverage ~= 4.5",
+              "coverage",
               "mock",
               "tox",
               "pytest",