Moved the existing BufferedBlockDevice to features/storage unittests and switched it to gmock.
Added gmock-based unit tests to all other BlockDevice classes.
SlicingBlockDevice test left as a module test.
GoogleTest allows you to check whether certain function throws errors.
For example:
ASSERT_ANY_THROW(mbed::HeapBlockDevice one(3050, 100));
or
ASSERT_NO_THROW(bd.init());
As MBED_ERROR is now only function that can throw errors, there is
no need to check the type of thrown object.
This uses HeapBlockDevice for providing the underlying storage block.
Check boundaries that slicingblockdevice do not overlow over to unassigned
blocks.
Michal Paszta
Antti Kauppila
Seppo Takalo