Bump pytest from 5.2.4 to 5.3.0 (#51)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.2.4 to 5.3.0.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest/compare/5.2.4...5.3.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Pipfile.lock

@@ -240,13 +240,6 @@
             "index": "pypi",
             "version": "==0.13.0"
         },
-        "atomicwrites": {
-            "hashes": [
-                "sha256:03472c30eb2c5d1ba9227e4c2ca66ab8287fbfbbda3888aa93dc2e28fc6811b4",
-                "sha256:75a9445bac02d8d058d5e1fe689654ba5a6556a1dfd8ce6ec55a0ed79866cfa6"
-            ],
-            "version": "==1.3.0"
-        },
         "attrs": {
             "hashes": [
                 "sha256:08a96c641c3a74e44eb59afb61a24f2cb9f4d7188748e76ba4bb5edfa3cb7d1c",
@@ -619,11 +612,11 @@
         },
         "pytest": {
             "hashes": [
-                "sha256:8e256fe71eb74e14a4d20a5987bb5e1488f0511ee800680aaedc62b9358714e8",
-                "sha256:ff0090819f669aaa0284d0f4aad1a6d9d67a6efdc6dd4eb4ac56b704f890a0d6"
+                "sha256:1897d74f60a5d8be02e06d708b41bf2445da2ee777066bd68edf14474fc201eb",
+                "sha256:f6a567e20c04259d41adce9a360bd8991e6aa29dd9695c5e6bd25a9779272673"
             ],
             "index": "pypi",
-            "version": "==5.2.4"
+            "version": "==5.3.0"
         },
         "pytest-asyncio": {
             "hashes": [