Adds a ReadGPIO block

Signed-off-by: Oren Leiman <oleiman@neutral.io>
Adds a WriteGPIO block

Signed-off-by: Oren Leiman <oleiman@neutral.io>
Monitor block emits True or False depending on whether the pin in question is set to pull up or down

Signed-off-by: Oren Leiman <oleiman@neutral.io>