Add missing import and fix function calls in cli

- Add missing `PipenvOptionsError` import to `pipenv.cli.command`
- Fix calls to `click.echo` (should be just `echo`)
- Fixes #4286

Signed-off-by: Dan Ryan <dan.ryan@canonical.com>

news/4286.bugfix.rst

@@ -0,0 +1 @@
+Corrected a missing exception import and invalid function call invocations in ``pipenv.cli.command``.

pipenv/cli/command.py

@@ -9,6 +9,7 @@
 )
 
 from ..__version__ import __version__
+from ..exceptions import PipenvOptionsError
 from ..patched import crayons
 from ..vendor import click_completion, delegator
 from .options import (
@@ -298,6 +299,7 @@ def uninstall(
     if retcode:
         sys.exit(retcode)
 
+
 LOCK_HEADER = """\
 #
 # These requirements were autogenerated by pipenv
@@ -307,11 +309,13 @@ def uninstall(
 #
 """
 
-LOCK_DEV_NOTE="""\
+
+LOCK_DEV_NOTE = """\
 # Note: in pipenv 2020.x, "--dev" changed to emit both default and development
 # requirements. To emit only development requirements, pass "--dev-only".
 """
 
+
 @cli.command(short_help="Generates Pipfile.lock.", context_settings=CONTEXT_SETTINGS)
 @lock_options
 @pass_state
@@ -342,10 +346,10 @@ def lock(
                 header_options.append("--dev-only")
             elif dev:
                 header_options.append("--dev")
-            click.echo(LOCK_HEADER.format(options=" ".join(header_options)))
+            echo(LOCK_HEADER.format(options=" ".join(header_options)))
             # TODO: Emit pip-compile style header
             if dev and not dev_only:
-                click.echo(LOCK_DEV_NOTE)
+                echo(LOCK_DEV_NOTE)
         # Setting "emit_requirements=True" means do_init() just emits the
         # install requirements file to stdout, it doesn't install anything
         do_init(
@@ -356,7 +360,7 @@ def lock(
             pre=state.installstate.pre,
         )
     elif state.lockoptions.dev_only:
-        raise exceptions.PipenvOptionsError(
+        raise PipenvOptionsError(
             "--dev-only",
             "--dev-only is only permitted in combination with --requirements. "
             "Aborting."