Added env for Itead Sonoff SV to create prebuild image (thanks to @akasma74, #698)

code/platformio.ini

@@ -710,6 +710,17 @@ upload_flags = --auth=fibonacci --port 8266
 monitor_baud = 115200
 extra_scripts = ${common.extra_scripts}
 
+[env:itead-sonoff-sv]
+platform = ${common.platform}
+framework = arduino
+board = esp01_1m
+board_flash_mode = dout
+lib_deps = ${common.lib_deps}
+lib_ignore = ${common.lib_ignore}
+build_flags = ${common.build_flags_1m} -DITEAD_SONOFF_SV
+monitor_baud = 115200
+extra_scripts = ${common.extra_scripts}
+
 # ------------------------------------------------------------------------------
 
 [env:electrodragon-wifi-iot]