revered unrelated changes

Author: daniel-sanche

packages/google-cloud-firestore/.coveragerc

@@ -2,7 +2,6 @@
 branch = True
 
 [report]
-fail_under = 99
 show_missing = True
 omit =
     google/cloud/firestore/__init__.py

packages/sqlalchemy-spanner/.coveragerc

@@ -85,7 +85,6 @@ class = StreamHandler
 UNIT_TEST_STANDARD_DEPENDENCIES = [
     "mock",
     "pytest",
-    "pytest-cov",
 ]
 
 UNIT_TEST_EXTERNAL_DEPENDENCIES = [
@@ -369,18 +368,7 @@ def unit(session, test_type):
             *UNIT_TEST_DEPENDENCIES,
         )
         session.install(".")
-        session.run(
-            "py.test",
-            "--quiet",
-            "--cov=google.cloud.sqlalchemy_spanner",
-            "--cov=tests/unit",
-            "--cov-append",
-            "--cov-config=.coveragerc",
-            "--cov-report=",
-            "--cov-fail-under=0",
-            os.path.join("tests/unit"),
-            *session.posargs,
-        )
+        session.run("py.test", "--quiet", os.path.join("tests/unit"), *session.posargs)
         return