Rework tests a little bit

[AngheloAlf]

• Remove bash scripts in favor of a proper Makefile
• Remove hard Docker requirement on test scripts.
  • This should allow everybody to use the test scripts with or without Docker
• Change dec usage to hex on test.py
• Fix missing bss start on basic_app yaml
• Fix missing rodata on basic_app
• Add instructions to use the test (see test/README.md)
• Some other cleanups