fix: package.json & package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-ANSIREGEX-1583908

package.json

@@ -193,7 +193,7 @@
     "csscomb": "^4.2.0",
     "diff": "^3.4.0",
     "editorconfig": "^0.15.0",
-    "eslint": "^4.16.0",
+    "eslint": "^7.0.0",
     "event-kit": "^2.4.0",
     "expand-home-dir": "0.0.3",
     "extend": "^3.0.2",
@@ -213,7 +213,7 @@
     "remark": "6.0.1",
     "season": "^6.0.2",
     "semver": "^5.5.0",
-    "shell-env": "^0.3.0",
+    "shell-env": "^4.0.0",
     "space-pen": "5.1.2",
     "strip-json-comments": "^2.0.1",
     "temp": "^0.8.3",