fix: update codecov version to 3.8.3 and modify coverage reporting script

Author: manu4543

package-lock.json

@@ -27,7 +27,7 @@
         "@types/node": "^15.6.1",
         "babel-plugin-transform-class-properties": "^6.24.1",
         "chai": "^4.2.0",
-        "codecov": "^3.8.0",
+        "codecov": "^3.8.3",
         "formdata-node": "2.1.0",
         "mocha": "^7.0.1",
         "nyc": "^15.1.0",
@@ -47,7 +47,7 @@
         "build": "rm -rf dist*;rollup -c && yarn export-types",
         "test": "NODE_ENV=test nyc ./node_modules/mocha/bin/mocha --require ./test/setup.js \"test/**/*.js\"",
         "startSampleApp": "yarn build && cd samples/sample-app/ && yarn install && node index.js",
-        "report-coverage": "codecov"
+        "report-coverage": "nyc report --reporter=text-lcov > coverage.lcov && codecov"
     },
     "repository": {
         "type": "git",