Move linters from tools into tool_util

Also, update setup.py for tool_util package.

Ref: https://github.com/galaxyproject/galaxy/issues/8240

Note: `make updaterst` has not been run; waiting on
https://github.com/galaxyproject/galaxy/pull/8270

lib/galaxy/tool_util/lint.py

@@ -28,9 +28,9 @@ def lint_xml(tool_xml, level=LEVEL_ALL, fail_level=LEVEL_WARN, extra_modules=[],
 
 
 def lint_tool_source_with(lint_context, tool_source, extra_modules=[]):
-    import galaxy.tools.linters
+    import galaxy.tool_util.linters
     tool_xml = getattr(tool_source, "xml_tree", None)
-    linter_modules = submodules.import_submodules(galaxy.tools.linters, ordered=True)
+    linter_modules = submodules.import_submodules(galaxy.tool_util.linters, ordered=True)
     linter_modules.extend(extra_modules)
     for module in linter_modules:
         tool_type = tool_source.parse_tool_type() or "default"

lib/galaxy/tool_util/linters/inputs.py

@@ -1,6 +1,6 @@
 """This module contains a linting functions for tool inputs."""
 from galaxy.util import string_as_bool
-from ..lint_util import is_datasource
+from ._util import is_datasource
 
 
 def lint_inputs(tool_xml, lint_ctx):

lib/galaxy/tool_util/linters/tests.py

@@ -1,5 +1,5 @@
 """This module contains a linting functions for tool tests."""
-from ..lint_util import is_datasource
+from ._util import is_datasource
 
 
 # Misspelled so as not be picked up by nosetests.

packages/tool_util/setup.py

@@ -37,6 +37,7 @@ PACKAGES = [
     'galaxy.tool_util.deps.container_resolvers',
     'galaxy.tool_util.deps.mulled',
     'galaxy.tool_util.deps.resolvers',
+    'galaxy.tool_util.linters',
     'galaxy.tool_util.locations',
     'galaxy.tool_util.parser',
 ]