chore: add .editorconfig

Author: gajus

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true

.gitignore

@@ -3,9 +3,10 @@ coverage
 dist
 *.log
 .*
-!.README
+!.babelrc
+!.editorconfig
+!.eslintrc
 !.gitignore
 !.npmignore
-!.babelrc
+!.README
 !.travis.yml
-!.eslintrc