Need to add pre-reqs to the readme.

[wayner9]

The installation notes in the readme file do not mention that you first have to install npm and forever before you can install harmony-api. It says it has support forever but it doesn't say that you have to have forever running or else it will refuse to install. I ran the bootstrap script - and was told

echo "You don't have forever installed. You need to install it first."
echo
echo "Just install it with this command: "
echo 'sudo npm install forever -g'

Of course when you do the npm command it will fail if npm isn't installed.

The readme also doesn't talk about platforms although it does say "on some distros...". It should say that this should run on OS X and Linux, including Raspberry Pis. Will it run natively on Windows? Under the Ubuntu-Bash Shell on Windows 10?