readline function in FONAtest does not properly

[rowedonalde]

• Host machine: MacBook Pro (13-inch, Mid 2012), OSX 10.10.5
• Screen version: 4.00.03 (FAU) 23-Oct-06
• Screen command: screen /dev/cu.usbmodem1411 115200 -L
• Arduino board: Arduino UNO (R3)
• Arduino IDE version: 1.8.5
• FONA device: Adafruit FONA - Mini Cellular GSM Breakout uFL Version

After setting up the FONA and Arduino as described in the tutorial and "logging on" to the Arduino's serial connection using the screen command above, certain commands like that take input like r for "Read SMS #" work but those that use the readline function like c for "make phone Call" do not. Apparently the screen utility when used like so only sends ASCII carriage returns (0xD) and not line feeds (0xA). I have a PR incoming that treats those chars as equal line enders.