Refactor use_package_config=True to omit_package_config_in_test=False.

This makes the intention clear.

zest/releaser/pypi.py

@@ -306,7 +306,7 @@ def load_configs(self, pypirc_config_filename=DIST_CONFIG_FILE):
         pyproject_config = PyprojectTomlConfig()
         combined_config = {}
         config_files = [pypi_config]
-        if self.use_package_config:
+        if not self.omit_package_config_in_test:
             config_files.extend([setup_config, pyproject_config])
         for config in config_files:
             if config.zest_releaser_config() is not None:
@@ -328,9 +328,9 @@ def load_configs(self, pypirc_config_filename=DIST_CONFIG_FILE):
         self.config = combined_config
 
     def __init__(
-        self, pypirc_config_filename=DIST_CONFIG_FILE, use_package_config=True
+        self, pypirc_config_filename=DIST_CONFIG_FILE, omit_package_config_in_test=False
     ):
-        self.use_package_config = use_package_config
+        self.omit_package_config_in_test = omit_package_config_in_test
         self.load_configs(pypirc_config_filename=pypirc_config_filename)
 
     def want_release(self):

zest/releaser/tests/pypi.txt

@@ -164,15 +164,15 @@ zest.releaser, which now contains a setup.cfg.
 
 We can ask for the result like this, which by default is True:
 
-    >>> zestreleaserconfig = pypi.ZestReleaserConfig(pypirc_config_filename=pypirc_both, use_package_config=False)
+    >>> zestreleaserconfig = pypi.ZestReleaserConfig(pypirc_config_filename=pypirc_both, omit_package_config_in_test=True)
     >>> zestreleaserconfig.create_wheel()
     True
 
 We can also specify to not create the wheel, even when (universal) wheels could be created:
 
     >>> pypirc_no_create = pkg_resources.resource_filename(
     ...     'zest.releaser.tests', 'pypirc_universal_nocreate.txt')
-    >>> zestreleaserconfig = pypi.ZestReleaserConfig(pypirc_config_filename=pypirc_no_create, use_package_config=False)
+    >>> zestreleaserconfig = pypi.ZestReleaserConfig(pypirc_config_filename=pypirc_no_create, omit_package_config_in_test=True)
     >>> zestreleaserconfig.create_wheel()
     False