Bump postcss from 7.0.17 to 7.0.39

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.17 to 7.0.39.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/7.0.39/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.17...7.0.39)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
...

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

package-lock.json

@@ -4670,6 +4670,12 @@
       "integrity": "sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns=",
       "dev": true
     },
+    "picocolors": {
+      "version": "0.2.1",
+      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-0.2.1.tgz",
+      "integrity": "sha512-cMlDqaLEqfSaW8Z7N5Jw+lyIW869EzT73/F5lhtY9cLGoVxSXznfgfXMO0Z5K0o0Q2TkTXq+0KFsdnSe3jDViA==",
+      "dev": true
+    },
     "pify": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
@@ -4760,25 +4766,13 @@
       "dev": true
     },
     "postcss": {
-      "version": "7.0.17",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-7.0.17.tgz",
-      "integrity": "sha512-546ZowA+KZ3OasvQZHsbuEpysvwTZNGJv9EfyCQdsIDltPSWHAeTQ5fQy/Npi2ZDtLI3zs7Ps/p6wThErhm9fQ==",
+      "version": "7.0.39",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-7.0.39.tgz",
+      "integrity": "sha512-yioayjNbHn6z1/Bywyb2Y4s3yvDAeXGOyxqD+LnVOinq6Mdmd++SW2wUNVzavyyHxd6+DxzWGIuosg6P1Rj8uA==",
       "dev": true,
       "requires": {
-        "chalk": "^2.4.2",
-        "source-map": "^0.6.1",
-        "supports-color": "^6.1.0"
-      },
-      "dependencies": {
-        "supports-color": {
-          "version": "6.1.0",
-          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-6.1.0.tgz",
-          "integrity": "sha512-qe1jfm1Mg7Nq/NSh6XE24gPXROEVsWHxC1LIx//XNlD9iw7YZQGjZNjYN7xGaEG6iKdA8EtNFW6R0gjnVXp+wQ==",
-          "dev": true,
-          "requires": {
-            "has-flag": "^3.0.0"
-          }
-        }
+        "picocolors": "^0.2.1",
+        "source-map": "^0.6.1"
       }
     },
     "postcss-load-config": {