fix(deps): specify all versions as exact versions

All versions in package.json are now specified as exact versions
(matching the versions specified by yarn.lock, not package.json) to
hopefully minimize yarn.lock desync from bad merge conflict resolution.

Also include yarnrc to install exact versions by default, and explicit
dependabot config to make sure versions are bumped correctly.

Also drop `native-url`, since preact-cli was updated in a merge commit
and is now no longer missing dependencies.

Author: ethanwu10

.dependabot/config.yml

@@ -0,0 +1,6 @@
+version: 1
+update_configs:
+  - package_manager: javascript
+    directory: /
+    update_schedule: weekly
+    version_requirement_updates: increase_versions

.yarnrc

@@ -0,0 +1 @@
+save-prefix ""

package.json

@@ -26,67 +26,66 @@
     }
   },
   "dependencies": {
-    "@google-cloud/storage": "^5.0.1",
-    "ajv": "^6.12.2",
-    "data-uri-to-buffer": "^3.0.0",
-    "dotenv": "^8.2.0",
-    "email-validator": "^2.0.4",
-    "express": "^4.17.1",
-    "got": "^11.1.4",
-    "helmet": "^3.22.0",
-    "jss-plugin-global": "^10.1.1",
-    "mustache": "^4.0.0",
-    "node-pg-migrate": "^5.0.0",
-    "nodemailer": "^6.4.6",
-    "pg": "^8.2.1",
-    "redis": "^3.0.2",
-    "uuid": "^8.1.0"
+    "@google-cloud/storage": "5.0.1",
+    "ajv": "6.12.2",
+    "data-uri-to-buffer": "3.0.0",
+    "dotenv": "8.2.0",
+    "email-validator": "2.0.4",
+    "express": "4.17.1",
+    "got": "11.1.4",
+    "helmet": "3.22.0",
+    "jss-plugin-global": "10.1.1",
+    "mustache": "4.0.1",
+    "node-pg-migrate": "5.0.0",
+    "nodemailer": "6.4.6",
+    "pg": "8.2.1",
+    "redis": "3.0.2",
+    "uuid": "8.1.0"
   },
   "devDependencies": {
-    "@types/express": "^4.17.6",
-    "@typescript-eslint/eslint-plugin": "^2.34.0",
-    "@typescript-eslint/parser": "^2.34.0",
-    "ava": "^3.8.2",
-    "babel-eslint": "^10.0.3",
-    "babel-plugin-transform-export-extensions": "^6.22.0",
-    "cirrus-ui": "^0.5.5",
-    "commitizen": "^4.1.2",
-    "compression": "^1.7.4",
-    "concurrently": "^5.2.0",
-    "cpy-cli": "^3.1.1",
-    "cross-env": "^7.0.2",
+    "@types/express": "4.17.6",
+    "@typescript-eslint/eslint-plugin": "2.34.0",
+    "@typescript-eslint/parser": "2.34.0",
+    "ava": "3.8.2",
+    "babel-eslint": "10.1.0",
+    "babel-plugin-transform-export-extensions": "6.22.0",
+    "cirrus-ui": "0.5.5",
+    "commitizen": "4.1.2",
+    "compression": "1.7.4",
+    "concurrently": "5.2.0",
+    "cpy-cli": "3.1.1",
+    "cross-env": "7.0.2",
     "cz-conventional-changelog": "3.2.0",
-    "eslint": "^6.8.0",
-    "eslint-config-preact": "^1.1.1",
-    "eslint-config-standard": "^14.1.1",
-    "eslint-plugin-ava": "^10.3.0",
-    "eslint-plugin-import": "^2.20.2",
-    "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-promise": "^4.2.1",
-    "eslint-plugin-standard": "^4.0.1",
-    "faker": "^4.1.0",
-    "get-port": "^5.1.1",
-    "glob": "^7.1.6",
-    "husky": "^4.2.5",
-    "jss": "^10.0.4",
-    "jss-camel-case": "^6.1.0",
-    "jss-nested": "^6.0.1",
-    "jss-vendor-prefixer": "^8.0.1",
-    "linkstate": "^1.1.1",
-    "loader-utils": "^2.0.0",
-    "native-url": "^0.3.1",
-    "nodemon": "^2.0.4",
-    "nyc": "^15.0.1",
-    "pascal-case": "^3.1.1",
-    "preact": "^10.4.4",
-    "preact-cli": "^3.0.0-rc.13",
-    "preact-markup": "^2.0.0",
-    "preact-router": "^3.2.1",
-    "purgecss-webpack-plugin": "^2.2.0",
-    "snarkdown": "^1.2.2",
-    "supertest": "^4.0.2",
-    "svg-sprite-loader": "^5.0.0",
-    "typescript": "^3.9.3"
+    "eslint": "6.8.0",
+    "eslint-config-preact": "1.1.1",
+    "eslint-config-standard": "14.1.1",
+    "eslint-plugin-ava": "10.3.0",
+    "eslint-plugin-import": "2.20.2",
+    "eslint-plugin-node": "11.1.0",
+    "eslint-plugin-promise": "4.2.1",
+    "eslint-plugin-standard": "4.0.1",
+    "faker": "4.1.0",
+    "get-port": "5.1.1",
+    "glob": "7.1.6",
+    "husky": "4.2.5",
+    "jss": "10.1.1",
+    "jss-camel-case": "6.1.0",
+    "jss-nested": "6.0.1",
+    "jss-vendor-prefixer": "8.0.1",
+    "linkstate": "1.1.1",
+    "loader-utils": "2.0.0",
+    "nodemon": "2.0.4",
+    "nyc": "15.0.1",
+    "pascal-case": "3.1.1",
+    "preact": "10.4.4",
+    "preact-cli": "3.0.0-rc.14",
+    "preact-markup": "2.0.0",
+    "preact-router": "3.2.1",
+    "purgecss-webpack-plugin": "2.2.0",
+    "snarkdown": "1.2.2",
+    "supertest": "4.0.2",
+    "svg-sprite-loader": "5.0.0",
+    "typescript": "3.9.3"
   },
   "description": "rctf is RedpwnCTF's CTF platform. It is developed and maintained by the [redpwn](https://redpwn.net) CTF team.",
   "repository": {