Prepare for Black autoformatting: dependencies, string staging, single-quote string override

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "8f51706fcfb278497a6d3083109744210150dc3c644ead11eda3e3cd806e2e14"
+            "sha256": "019b67ce05e7e68766ba54ddbfd3e2faf5dd81c7ded79f80ff3ef85b0017c99d"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -25,6 +25,20 @@
             "index": "pypi",
             "version": "==1.0.7"
         },
+        "appdirs": {
+            "hashes": [
+                "sha256:9e5896d1372858f8dd3344faf4e5014d21849c756c8d5701f78f8a103b372d92",
+                "sha256:d8b24664561d0d34ddfaec54636d502d7cea6e29c3eaf68f3df6180863e2166e"
+            ],
+            "version": "==1.4.3"
+        },
+        "attrs": {
+            "hashes": [
+                "sha256:69c0dbf2ed392de1cb5ec704444b08a5ef81680a61cb899dc08127123af36a79",
+                "sha256:f0b870f674851ecbfbbbd364d6b5cbdff9dcedbc7f3f5e18a6891057f21fe399"
+            ],
+            "version": "==19.1.0"
+        },
         "backcall": {
             "hashes": [
                 "sha256:38ecd85be2c1e78f77fd91700c76e14667dc21e2713b63876c0eb901196e01e4",
@@ -32,6 +46,14 @@
             ],
             "version": "==0.1.0"
         },
+        "black": {
+            "hashes": [
+                "sha256:09a9dcb7c46ed496a9850b76e4e825d6049ecd38b611f1224857a79bd985a8cf",
+                "sha256:68950ffd4d9169716bcb8719a56c07a2f4485354fec061cdd5910aa07369731c"
+            ],
+            "index": "pypi",
+            "version": "==19.3b0"
+        },
         "click": {
             "hashes": [
                 "sha256:2335065e6395b9e67ca716de5f7526736bfa6ceead690adf616d925bdc622b13",
@@ -86,6 +108,13 @@
             "index": "pypi",
             "version": "==0.8.1"
         },
+        "flake8-quotes": {
+            "hashes": [
+                "sha256:10c9af6b472d4302a8e721c5260856c3f985c5c082b04841aefd2f808ac02038"
+            ],
+            "index": "pypi",
+            "version": "==2.0.1"
+        },
         "greenlet": {
             "hashes": [
                 "sha256:000546ad01e6389e98626c1367be58efa613fa82a1be98b0c6fc24b563acc6d0",
@@ -304,6 +333,13 @@
             ],
             "version": "==6.10.0"
         },
+        "toml": {
+            "hashes": [
+                "sha256:229f81c57791a41d65e399fc06bf0848bab550a9dfd5ed66df18ce5f05e73d5c",
+                "sha256:235682dd292d5899d361a811df37e04a8828a5b1da3115886b73cf81ebc9100e"
+            ],
+            "version": "==0.10.0"
+        },
         "traitlets": {
             "hashes": [
                 "sha256:9c4bd2d267b7153df9152698efb1050a5d84982d3384a37b2c1f7723ba3e7835",