chore(*): Added editorconfig

editorconfig configures editors to use the correct indent size and
style.

[skip ci]

Author: johanneswuerbach

.editorconfig

@@ -0,0 +1,14 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+
+[*.go]
+indent_style = tab