Remove trollius from NixOS CI jobs

[sajith]

On NixOS, autobahn has trollius as an optional dependency. Trollius is no longer maintained, and it has started to fail on CI with this error:

running test
running egg_info
writing requirements to trollius.egg-info/requires.txt
writing trollius.egg-info/PKG-INFO
writing top-level names to trollius.egg-info/top_level.txt
writing dependency_links to trollius.egg-info/dependency_links.txt
reading manifest file 'trollius.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no files found matching 'release.py'
writing manifest file 'trollius.egg-info/SOURCES.txt'
running build_ext
gcc  -I. -Icrypto/include -Iinclude -fPIC -pthread -m64 -Wa,--noexecstack -Wall -O3 -DOPENSSL_USE_NODELETE -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DVPAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX25519_ASM -DPOLY1305_ASM -DOPENSSLDIR="\"/nix/store/z14n23kmhfnin06hnnxr7b1b59kxh0qn-openssl-1.1.1d/etc/ssl\"" -DENGINESDIR="\"/nix/store/z14n23kmhfnin06hnnxr7b1b59kxh0qn-openssl-1.1.1d/lib/engines-1.1\"" -DNDEBUG  -MMD -MF crypto/evp/e_bf.d.tmp -MT crypto/evp/e_bf.o -c -o crypto/evp/e_bf.o crypto/evp/e_bf.c
trollius.test_support (unittest.loader.ModuleImportFailure) ... ERROR

======================================================================
ERROR: trollius.test_support (unittest.loader.ModuleImportFailure)
----------------------------------------------------------------------
ImportError: Failed to import test module: trollius.test_support
Traceback (most recent call last):
  File "/nix/store/0yz15vp6xvaixrkls7y85r65d95jc0m4-python-2.7.17/lib/python2.7/unittest/loader.py", line 254, in _find_tests
    module = self._get_module_from_name(name)
  File "/nix/store/0yz15vp6xvaixrkls7y85r65d95jc0m4-python-2.7.17/lib/python2.7/unittest/loader.py", line 232, in _get_module_from_name
    __import__(name)
  File "/tmp/nix-build-python2.7-trollius-2.2.post1.drv-0/trollius-2.2.post1/trollius/test_support.py", line 133, in <module>
    IPV6_ENABLED = _is_ipv6_enabled()
  File "/tmp/nix-build-python2.7-trollius-2.2.post1.drv-0/trollius-2.2.post1/trollius/test_support.py", line 124, in _is_ipv6_enabled
    sock.bind((HOSTv6, 0))
  File "/nix/store/0yz15vp6xvaixrkls7y85r65d95jc0m4-python-2.7.17/lib/python2.7/socket.py", line 228, in meth
    return getattr(self._sock,name)(*args)
error: [Errno 99] Cannot assign requested address


----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (errors=1)
Test failed: <unittest.runner.TextTestResult run=1 errors=1 failures=0>
error: Test failed: <unittest.runner.TextTestResult run=1 errors=1 failures=0>
builder for '/nix/store/8xq7g02snnid5a5gdz8xgj0yi9pmn1ms-python2.7-trollius-2.2.post1.drv' failed with exit code 1
cannot build derivation '/nix/store/vk5jsrzmr027zpmsm2ffcf2didiq1nyr-python2.7-autobahn-19.8.1.drv': 1 dependencies couldn't be built
building '/nix/store/f75g5zdddar12d5mnkckzvc0bzisrv15-python2.7-setuptools_trial-0.6.0.drv'...
building '/nix/store/82kh190zmq4qs6jj0diqk0isiyjy9910-python2.7-txtorcon-19.0.0.drv'...
cannot build derivation '/nix/store/d80w8v913jzxav0d8k97xsqhg6m8pcp1-python2.7-tahoe-lafs-1.14.0.dev.drv': 1 dependencies couldn't be built
error: build of '/nix/store/d80w8v913jzxav0d8k97xsqhg6m8pcp1-python2.7-tahoe-lafs-1.14.0.dev.drv' failed

Exited with code exit status 100