Remove Travis references (wntrblm#403)

CONTRIBUTING.md

@@ -45,7 +45,7 @@ To run against a particular Python version:
     nox --session tests-3.9
 
 
-When you send a pull request Travis will handle running everything, but it is
+When you send a pull request the CI will handle running everything, but it is
 recommended to test as much as possible locally before pushing.
 
 ## Getting a sticker

nox/_options.py

@@ -402,6 +402,13 @@ def _session_completer(
         hidden=True,
         finalizer_func=_color_finalizer,
     ),
+    _option_set.Option(
+        "no_install",
+        "--no-install",
+        group=options.groups["secondary"],
+        action="store_true",
+        help="Skip invocations of session methods for installing packages.",
+    ),
 )
 
 

nox/sessions.py

@@ -418,6 +418,11 @@ def install(self, *args: str, **kwargs: Any) -> None:
 
         .. _pip: https://pip.readthedocs.org
         """
+
+        if self._runner.global_config.no_install:
+            logger.info("Skipping {} installation, as --no-install is set.".format(args[0]))
+            return None
+
         if not isinstance(
             self._runner.venv, (CondaEnv, VirtualEnv, PassthroughEnv)
         ):  # pragma: no cover

tests/test_sessions.py

@@ -199,6 +199,18 @@ def test_run_install_only(self, caplog):
 
         assert "install-only" in caplog.text
 
+    def test_run_no_install(self, caplog):
+        caplog.set_level(logging.INFO)
+        session, runner = self.make_session_and_runner()
+        runner.global_config.no_install = True
+
+        with mock.patch.object(nox.command, "run") as run:
+            assert session.install("eggs", "spam") is None
+
+        run.assert_not_called()
+
+        assert "no-install" in caplog.text
+
     def test_run_install_only_should_install(self):
         session, runner = self.make_session_and_runner()
         runner.global_config.install_only = True
@@ -500,6 +512,7 @@ class SessionNoSlots(nox.sessions.Session):
                 external="error",
             )
 
+
     def test_notify(self):
         session, runner = self.make_session_and_runner()
 
@@ -568,6 +581,7 @@ def make_runner(self):
         )
         return runner
 
+
     def test_properties(self):
         runner = self.make_runner()