use SDK rc.1, update dev dependencies

Author: eli-darkly

.eslintignore

@@ -1,2 +1,3 @@
 node_modules/
 test-types.js
+.eslintrc.js

package.json

@@ -11,17 +11,21 @@
   },
   "types": "./index.d.ts",
   "devDependencies": {
-    "@babel/core": "7.4.3",
-    "@babel/preset-env": "7.4.3",
+    "@babel/core": "^7.14.6",
+    "@babel/preset-env": "^7.14.5",
+    "@types/node": "^15.12.2",
     "aws-sdk": "^2.349.0",
-    "babel-jest": "24.7.1",
-    "eslint": "5.8.0",
-    "eslint-formatter-pretty": "1.3.0",
-    "jest": "24.7.1",
-    "jest-junit": "6.3.0",
-    "launchdarkly-js-test-helpers": "^1.0.0",
-    "launchdarkly-node-server-sdk": "^6.0.0-alpha.1",
-    "typescript": "^3.8.3"
+    "babel-jest": "^27.0.2",
+    "eslint": "^7.28.0",
+    "eslint-config-prettier": "^8.3.0",
+    "eslint-formatter-pretty": "^4.1.0",
+    "eslint-plugin-prettier": "^3.4.0",
+    "jest": "^27.0.4",
+    "jest-junit": "^12.2.0",
+    "launchdarkly-js-test-helpers": "^1.2.1",
+    "launchdarkly-node-server-sdk": "^6.0.0-rc.1",
+    "prettier": "^2.3.1",
+    "typescript": "^4.3.2"
   },
   "jest": {
     "rootDir": ".",
@@ -37,7 +41,7 @@
   },
   "peerDependencies": {
     "aws-sdk": "^2.349.0",
-    "launchdarkly-node-server-sdk": "^6.0.0-alpha.1"
+    "launchdarkly-node-server-sdk": "^6.0.0-rc.1"
   },
   "engines": {
     "node": ">= 12.0"