$ pip install --upgrade -r requirements.txt
Collecting flake8<4.0,>=3.7.9 (from -r requirements.txt (line 2))
  Downloading https://files.pythonhosted.org/packages/f8/1f/7ea40d1e4146ea55dbab41cda1376db092a75794914169aabd7e8d7a7def/flake8-3.7.9-py2.py3-none-any.whl (69kB)
     |¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦| 71kB 3.2MB/s
Collecting autopep8<2.0,>=1.4.4 (from -r requirements.txt (line 3))
  Using cached https://files.pythonhosted.org/packages/45/f3/24b437da561b6af4840c871fbbda32889ca304fc1f7b6cc3ada8b09f394a/autopep8-1.4.4.tar.gz
Collecting pycodestyle<3.0,>=2.5.0 (from -r requirements.txt (line 4))
  Using cached https://files.pythonhosted.org/packages/0e/0c/04a353e104d2f324f8ee5f4b32012618c1c86dd79e52a433b64fceed511b/pycodestyle-2.5.0-py2.py3-none-any.whl
Collecting PyYAML<6.0,>=5.2 (from -r requirements.txt (line 7))
  Downloading https://files.pythonhosted.org/packages/8d/c9/e5be955a117a1ac548cdd31e37e8fd7b02ce987f9655f5c7563c656d5dcb/PyYAML-5.2.tar.gz (265kB)
     |¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦| 266kB 6.1MB/s
Requirement already up-to-date: mock<3.0,>=2.0.0 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from -r requirements.txt (line 10)) (2.0.0)
Collecting salt==2019.2.2 (from -r requirements.txt (line 11))
  Downloading https://files.pythonhosted.org/packages/a3/99/b3e5c77b8383fdd04fce0161c2ee58a21633a37b3b8d8367d6449023eb8c/salt-2019.2.2.tar.gz (14.4MB)
     |¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦| 14.4MB 4.3kB/s
Collecting entrypoints<0.4.0,>=0.3.0 (from flake8<4.0,>=3.7.9->-r requirements.txt (line 2))
  Using cached https://files.pythonhosted.org/packages/ac/c6/44694103f8c221443ee6b0041f69e2740d89a25641e62fb4f2ee568f2f9c/entrypoints-0.3-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: mccabe<0.7.0,>=0.6.0 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from flake8<4.0,>=3.7.9->-r requirements.txt (line 2)) (0.6.1)
Collecting pyflakes<2.2.0,>=2.1.0 (from flake8<4.0,>=3.7.9->-r requirements.txt (line 2))
  Using cached https://files.pythonhosted.org/packages/84/f2/ed0ffb887f8138a8fe5a621b8c0bb9598bfb3989e029f6c6a85ee66628ee/pyflakes-2.1.1-py2.py3-none-any.whl
Requirement already satisfied, skipping upgrade: six>=1.9 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from mock<3.0,>=2.0.0->-r requirements.txt (line 10)) (1.11.0)
Requirement already satisfied, skipping upgrade: pbr>=0.11 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from mock<3.0,>=2.0.0->-r requirements.txt (line 10)) (3.1.1)
Requirement already satisfied, skipping upgrade: Jinja2 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (2.10)
Requirement already satisfied, skipping upgrade: msgpack!=0.5.5,>=0.5 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (0.5.6)
Requirement already satisfied, skipping upgrade: MarkupSafe in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (1.0)
Requirement already satisfied, skipping upgrade: requests>=1.0.0 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (2.18.4)
Requirement already satisfied, skipping upgrade: tornado<5.0,>=4.2.1 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (4.5.2)
Requirement already satisfied, skipping upgrade: pycrypto>=2.6.1 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (2.6.1)
Requirement already satisfied, skipping upgrade: pyzmq>=2.2.0 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from salt==2019.2.2->-r requirements.txt (line 11)) (16.0.3)
Requirement already satisfied, skipping upgrade: certifi>=2017.4.17 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from requests>=1.0.0->salt==2019.2.2->-r requirements.txt (line 11)) (2017.11.5)
Requirement already satisfied, skipping upgrade: urllib3<1.23,>=1.21.1 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from requests>=1.0.0->salt==2019.2.2->-r requirements.txt (line 11)) (1.22)
Requirement already satisfied, skipping upgrade: chardet<3.1.0,>=3.0.2 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from requests>=1.0.0->salt==2019.2.2->-r requirements.txt (line 11)) (3.0.4)
Requirement already satisfied, skipping upgrade: idna<2.7,>=2.5 in /usr/home/dereckson/dev/python/salt3/lib/python3.6/site-packages (from requests>=1.0.0->salt==2019.2.2->-r requirements.txt (line 11)) (2.6)
ERROR: salt 2019.2.2 has requirement PyYAML<5.1, but you'll have pyyaml 5.2 which is incompatible.
Installing collected packages: entrypoints, pycodestyle, pyflakes, flake8, autopep8, PyYAML, salt
  Found existing installation: pycodestyle 2.3.1
    Uninstalling pycodestyle-2.3.1:
      Successfully uninstalled pycodestyle-2.3.1
  Found existing installation: pyflakes 1.6.0
    Uninstalling pyflakes-1.6.0:
      Successfully uninstalled pyflakes-1.6.0
  Found existing installation: flake8 3.5.0
    Uninstalling flake8-3.5.0:
      Successfully uninstalled flake8-3.5.0
  Found existing installation: autopep8 1.3.3
    Uninstalling autopep8-1.3.3:
      Successfully uninstalled autopep8-1.3.3
  Running setup.py install for autopep8 ... done
  Found existing installation: PyYAML 3.12
    Uninstalling PyYAML-3.12:
      Successfully uninstalled PyYAML-3.12
  Running setup.py install for PyYAML ... done
  Found existing installation: salt 2018.3.1
    Uninstalling salt-2018.3.1:
      Successfully uninstalled salt-2018.3.1
...