Update the Docker to Base off of Ubuntu 20.04 (focal) rather than 18.04

[agroce]

• Right now, this doesn't work with Eclipser for known reasons

• Angora is also disabled, though I have no investigated why it fails (that is, it might fail on 18.04 also)

• Eclipser probably fails on 18.04 right now as well, just because we directly git clone 2.0, which we probably don't work with

[agroce]

Manticore, alas, seems to not be happy:

it runs but:

2020-12-10 13:55:59,041: [41440] m.n.c.abstractcpu:WARNING: Unimplemented instruction: 0x00000000004609c0:	f3 0f 1e fa	endbr64	
2020-12-10 13:55:59,051: [41440] m.n.c.abstractcpu:WARNING: Unimplemented instruction: 0x000000000041c4f0:	f3 0f 1e fa	endbr64	
2020-12-10 13:55:59,054: [41440] m.n.c.abstractcpu:WARNING: Unimplemented instruction: 0x000000000047b240:	f3 0f 1e fa	endbr64	
2020-12-10 13:55:59,065: [41440] m.c.worker:ERROR: Exception in state 0: DecodeException('Error decoding instruction @ 0x47b299')
Traceback (most recent call last):
  File "/home/user/.local/lib/python3.8/site-packages/manticore/native/cpu/abstractcpu.py", line 937, in decode_instruction
    insn = self.disasm.disassemble_instruction(code, pc)
  File "/home/user/.local/lib/python3.8/site-packages/manticore/native/cpu/disasm.py", line 78, in disassemble_instruction
    return next(self.disasm.disasm(code, pc))
StopIteration
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/user/.local/lib/python3.8/site-packages/manticore/core/worker.py", line 121, in run
    current_state.execute()
  File "/home/user/.local/lib/python3.8/site-packages/manticore/native/state.py", line 192, in execute
    result = self._platform.execute()
  File "/home/user/.local/lib/python3.8/site-packages/manticore/platforms/linux.py", line 2906, in execute
    self.current.execute()
  File "/home/user/.local/lib/python3.8/site-packages/manticore/native/cpu/abstractcpu.py", line 987, in execute
    insn = self.decode_instruction(curpc)
  File "/home/user/.local/lib/python3.8/site-packages/manticore/native/cpu/abstractcpu.py", line 939, in decode_instruction
    raise DecodeException(pc, code)
manticore.native.cpu.abstractcpu.DecodeException: Error decoding instruction @ 0x47b299
11:56

starts out looking ok:

user@8b06f1028970:~/deepstate/build_deepstate/examples$ deepstate-manticore ./Crash 
INFO:deepstate:Setting log level from DEEPSTATE_LOG: 2
INFO:deepstate.core.base:Setting log level from --min_log_level: 2
2020-12-10 13:55:53,926: [41440] m.n.manticore:INFO: Loading program ./Crash
2020-12-10 13:55:55,421: [41440] m.n.manticore:INFO: Loading program ./Crash
11:56

but then the unimplemented instruction stuff starts pouring out.

Same example works on my docker built using 18.04.

for now I'm going to call that too many of the tools DeepState relies on aren't 20.04 ready