Adapt project to various environments (windows and jetbrains IDE's)

To allow developers working on project without any inconveniences.

Different OS have handled line endings and environment variables
differently. Also each IDE has system files that should not be in
repository. So now we manage this points using cross-env package,
.editorconfig and .gitignore. And we can working on project in
different environments (such as windows and jetbrains IDE's)

Author: AinuraAliieva

.editorconfig

@@ -0,0 +1,7 @@
+# http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true

.gitignore

@@ -7,3 +7,4 @@ dist
 # misc
 .DS_Store
 npm-debug.log
+/.idea

package-lock.json

@@ -39,6 +39,7 @@
     "babel-preset-env": "^1.6.1",
     "babel-preset-react": "^6.24.1",
     "clean-webpack-plugin": "^0.1.17",
+    "cross-env": "^5.1.3",
     "css-loader": "^0.28.7",
     "eslint": "^4.9.0",
     "eslint-config-airbnb": "^16.1.0",
@@ -61,7 +62,7 @@
   "scripts": {
     "lint": "eslint --ignore-path .gitignore --ext js,jsx .",
     "build": "webpack",
-    "start": "NODE_ENV=development webpack-dev-server --open",
+    "start": "cross-env NODE_ENV=development webpack-dev-server --open",
     "test": "jest"
   }
 }