python-language-server: 0.19.0 -> 0.21.2

[Mic92]

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Fits CONTRIBUTING.md.

---

[Mic92]

@GrahamcOfBorg build python3Packages.python-language-server python2Packages.python-language-server

[GrahamcOfBorg]

Success on x86_64-linux (full log)

Attempted: python3Packages.python-language-server, python2Packages.python-language-server

Partial log (click to expand)

test/test_uris.py                          17      2    88%
test/test_utils.py                         56      0   100%
test/test_workspace.py                     33      0   100%
-----------------------------------------------------------
TOTAL                                    1688    209    88%
Coverage HTML written to dir htmlcov

===================== 67 passed, 5 skipped in 7.67 seconds =====================
/nix/store/as79pjwkwardw59xq23j0nsph51xhwwp-python3.6-python-language-server-0.21.2
/nix/store/19pjs01f2w56628j0wfdf7w658c3x2f8-python2.7-python-language-server-0.21.2

[GrahamcOfBorg]

Success on x86_64-darwin (full log)

Attempted: python3Packages.python-language-server, python2Packages.python-language-server

Partial log (click to expand)

test/test_uris.py                          17      2    88%
test/test_utils.py                         56      0   100%
test/test_workspace.py                     33      0   100%
-----------------------------------------------------------
TOTAL                                    1688    210    88%
Coverage HTML written to dir htmlcov

===================== 67 passed, 5 skipped in 7.65 seconds =====================
/nix/store/0pcpqpy373z66q6z20rqp5k9rydxzycw-python3.6-python-language-server-0.21.2
/nix/store/q9irv4fnqn3jczm6bjxbijrpm68vahrh-python2.7-python-language-server-0.21.2

[GrahamcOfBorg]

Success on aarch64-linux (full log)

Attempted: python3Packages.python-language-server, python2Packages.python-language-server

Partial log (click to expand)

test/test_utils.py                         56      0   100%
test/test_workspace.py                     33      0   100%
-----------------------------------------------------------
TOTAL                                    1688    209    88%
Coverage HTML written to dir htmlcov

==================== 67 passed, 5 skipped in 28.42 seconds =====================
2018-09-12 08:06:43,024 UTC - DEBUG - pyls.python_ls - parent process 1 is still alive
/nix/store/7yl0bi5nk9jqarr7hi7fp763g0k57q5i-python3.6-python-language-server-0.21.2
/nix/store/qyq3ylkypq0d7yd3ybrz84b1q3hcfv1j-python2.7-python-language-server-0.21.2