Add .editorconfig file for consistent styling (#76)

This should take effect when editors with [EditorConfig](http://editorconfig.org/) support are used.

Signed-off-by: Antonis Kalipetis <akalipetis@gmail.com>

.editorconfig

@@ -0,0 +1,14 @@
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+indent_style = space
+indent_size = 4
+
+# Tab indentation (no size specified)
+[{Makefile,*.go}]
+indent_style = tab