Add setup.cfg for convenience commands for translations

Add Babel options catered to the locale/ directory of the pygeoapi repo
so that the following convenient commands can be used without additional
command-line options for managing translation files:

	python3 setup.py compile_catalog
	python3 setup.py extract_messages
	python3 setup.py init_catalog
	python3 setup.py update_catalog

See https://babel.pocoo.org/en/latest/setup.html

babel-mapping.ini

@@ -1,3 +1,3 @@
 [python: **.py]
 [jinja2: **/templates/**.html]
-extensions=jinja2.ext.i18n,jinja2.ext.autoescape,jinja2.ext.with_
+extensions=jinja2.ext.i18n,jinja2.ext.autoescape,jinja2.ext.with_

setup.cfg

@@ -0,0 +1,14 @@
+[compile_catalog]
+directory = locale
+
+[extract_messages]
+mapping_file = babel-mapping.ini
+output_file = locale/messages.pot
+
+[init_catalog]
+input_file = locale/messages.pot
+output_dir = locale
+
+[update_catalog]
+input_file = locale/messages.pot
+output_dir = locale