Add environment $LOOKUP plugin

remove support for multiple vars

lib/ansible/runner/lookup_plugins/env.py

+# (c) 2012, Jan-Piet Mens <jpmens(at)gmail.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+from ansible import utils, errors
+import os
+
+class LookupModule(object):
+
+    def __init__(self, basedir=None, **kwargs):
+        self.basedir = basedir
+
+    def run(self, terms, **kwargs):
+
+        var = terms.split()[0]
+        return os.getenv(var, '')