Expected result
  ===============
  Use the provided shell commands, to read and write pages from/to the MCU's
  internal flash memory. For altering the data in a flash page, use a sequence
  similar to this:
  - read some page from the flash, this will load this page into a local buffer
  ```
  read 100
  ```
  - edit the contents of the local buffer, here we write 'Hello_RIOT' to position
    100
  ```
  edit 100 Hello_RIOT
  ```
  - write the local buffer to any target page in the flash. CAUTION: if you
    override any page, that contains program code (or even the interrupt vector),
    you will most like encounter hard faults and crashes which can only be fixed
    by re-flashing the node...
  ```
  write 100
  ```
  - check if the contents were written
  ```
  dump 100
  ```
  - now power off the node, wait a bit and power it back on. The contents of the
    page written previously should still be there
  
  What else to check:
  - Erase a page with previously known contents, to make sure the erasing works
  - also check the pages before and after the targeted page, to see if the page
    size is correct, and that you are only erasing the actual page and not any
    parts of the neighboring page.
  
  Background
  ==========
  This test provides you with tools to test implementations of the `flashpage`
  peripheral driver interface.