Teensy I2c speed

[fimtrey]

Hi,

I'm using a Teensy LC. With each flush, the image was shifted by one pixel.

I finally realised that the teensy wasn't happy about switching the I2c clock all the time.
So I got it running with specifying the clocks in the constructor:
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1, 400000UL, 400000UL);

In #107 @PaulStoffregen proposed to use 400 kHz teensy for all Teensys. Is there a good place to notify further users or implement a default clock speed for teensy.

[ladyada]

you could add a PR to the example for teensy's