added linter settings

.eslintrc.json

@@ -0,0 +1,46 @@
+{
+    "extends": [
+        "eslint:recommended",
+        "plugin:react/recommended"
+    ],
+    "env": {
+        "browser": true,
+        "commonjs": true,
+        "es6": true,
+        "node": true,
+        "jest/globals": true
+    },
+    "globals": {
+        "chrome": false
+    },
+    "plugins": [
+        "jest"
+    ],
+    "parser": "babel-eslint",
+    "parserOptions": {
+        "ecmaVersion": 7,
+        "ecmaFeatures": {
+            "experimentalObjectRestSpread": true,
+            "experimentalDecorators": true,
+            "jsx": true
+        },
+        "sourceType": "module"
+    },
+    "rules": {
+        "strict": 0,
+        "array-callback-return": "warn",
+        "getter-return": "warn",
+        "no-const-assign": "warn",
+        "no-this-before-super": "warn",
+        "no-undef": "warn",
+        "no-unreachable": "warn",
+        "no-unused-vars": ["warn", { "argsIgnorePattern": "^_" }],
+        "constructor-super": "warn",
+        "valid-typeof": "warn",
+        "jest/no-disabled-tests": "warn",
+        "jest/no-focused-tests": "error",
+        "jest/no-identical-title": "error",
+        "jest/prefer-to-have-length": "warn",
+        "jest/valid-expect": "error"
+    }
+}