A6 A7 gateway (GSM GPRS) (#195)

* init 2G gateway with SMS sending and receiving

* A6lib add

* add 2Ggateway call from setup and loop

* add schematic and image

lib/A6lib/.editorconfig

@@ -0,0 +1,21 @@
+# EditorConfig file: http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = false
+
+# 4 space indentation
+[*.{cpp,h}]
+indent_style = space
+indent_size = 4
+trim_trailing_whitespace = true
+
+# 2 space indentation
+[*.json]
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true