Replace bumpversion with bump2version.

It's pretty much an in-place replacement but bumpversion is not
maintained anymore and bump2version is.

Pipfile

@@ -5,7 +5,7 @@ verify_ssl = true
 
 [dev-packages]
 pre-commit = "*"
-bumpversion = {version = "*",markers = "python_version >= '3.6'"}
+bump2version = {version = "*",markers = "python_version >= '3.6'"}
 twine = "*"
 template = {editable = true,path = "."}
 pytest = "*"

Pipfile.lock

 {
     "_meta": {
         "hash": {
-            "sha256": "421f66614cac0e4a683865046a25ea8c50879b524bb96effc1234c45c9e7829c"
+            "sha256": "b205194a7b41375aa52bf0f496c5a4fffa16a8cea2d4abfeb7a490dec8105188"
         },
         "pipfile-spec": 6,
         "requires": {},
@@ -44,17 +44,9 @@
                 "sha256:37f927ea17cde7ae2d7baf832f8e80ce3777624554a653006c9144f8017fe410",
                 "sha256:762cb2bfad61f4ec8e2bdf452c7c267416f8c70dd9ecb1653fd0bbb01fa936e6"
             ],
-            "markers": "python_version >= '3.5'",
-            "version": "==1.0.1"
-        },
-        "bumpversion": {
-            "hashes": [
-                "sha256:4ba55e4080d373f80177b4dabef146c07ce73c7d1377aabf9d3c3ae1f94584a6",
-                "sha256:4eb3267a38194d09f048a2179980bb4803701969bff2c85fa8f6d1ce050be15e"
-            ],
             "index": "pypi",
             "markers": "python_version >= '3.6'",
-            "version": "==0.6.0"
+            "version": "==1.0.1"
         },
         "certifi": {
             "hashes": [