Test downloads via insecure http

[NicoHood]

Most test files are downloaded via insecure http and can be changed to https:

Downloading http://downloads.arduino.cc/cores/avr-1.6.10.tar.bz2
Downloading http://downloads.arduino.cc/cores/sam-1.6.7.tar.bz2
Downloading http://downloads.arduino.cc/cores/samd-1.6.5.tar.bz2
Downloading http://downloads.arduino.cc/tools/avrdude-6.0.1-arduino5-x86_64-pc-linux-gnu.tar.bz2
Downloading http://downloads.arduino.cc/tools/avr-gcc-4.8.1-arduino5-x86_64-pc-linux-gnu.tar.bz2
Downloading http://downloads.arduino.cc/gcc-arm-none-eabi-4.8.3-2014q1-linux64.tar.gz
Downloading http://downloads.arduino.cc/tools/ctags-5.8-arduino11-x86_64-pc-linux-gnu.tar.bz2
Downloading http://downloads.arduino.cc/bossac-1.6.1-arduino-x86_64-linux-gnu.tar.gz
Downloading http://downloads.arduino.cc/bossac-1.5-arduino2-x86_64-linux-gnu.tar.gz
Downloading http://downloads.arduino.cc/tools/OpenOCD-0.9.0-arduino-x86_64-linux-gnu.tar.bz2
Downloading http://downloads.arduino.cc/CMSIS-4.0.0.tar.bz2
Downloading http://downloads.arduino.cc/gcc-arm-none-eabi-4.8.3-2014q1-linux64.tar.gz
Downloading https://redbearlab.github.io/arduino/Blend/blend_boards.zip
Downloading http://downloads.arduino.cc/libraries/arduino-libraries/Audio-1.0.4.zip
Downloading http://downloads.arduino.cc/libraries/adafruit/Adafruit_PN532-1.0.0.zip
Downloading http://downloads.arduino.cc/libraries/arduino-libraries/Bridge-1.6.1.zip
Downloading http://downloads.arduino.cc/libraries/PaulStoffregen/CapacitiveSensor-0.5.0.zip
Downloading http://downloads.arduino.cc/libraries/arduino-libraries/Ethernet-1.1.1.zip
Downloading http://downloads.arduino.cc/libraries/arduino-libraries/Robot_IR_Remote-1.0.2.zip
Downloading http://downloads.arduino.cc/libraries/FastLED/FastLED-3.1.0.zip