Add editorconfig

.editorconfig

+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+charset = utf-8
+max_line_length = 100
+
+# Tab indentation (no size specified)
+[Makefile]
+indent_style = tab
+
+[lib/**.js]
+indent_size = 2
+
+[{package.json,.travis.yml}]
+indent_style = space
+indent_size = 2
+
+[*.{json,yml}]
+indent_size = 2
+
+