Switch more generateconfs defaults to AUTO with dynamic look up for greater

flexibility on non-deployment setups and in order to eventually be able to
eliminate the dynamic values from PR72 in mig.shared.defaults .

Author: jonasbardino

mig/shared/install.py

@@ -440,7 +440,7 @@ def generate_confs(
     if group == keyword_auto:
         group = expanded['group'] = grp.getgrgid(os.getgid())[0]
 
-    if admin_email is keyword_auto:
+    if admin_email == keyword_auto:
         admin_email = expanded['admin_email'] = user
 
     # Finalize a destination path up-front
@@ -449,13 +449,13 @@ def generate_confs(
 
     # Expand any path information marked as "AUTO" based on the environment
     # NOTE: we do NOT follow symlinks here as they should remain transparent
-    if mig_code is keyword_auto:
+    if mig_code == keyword_auto:
         mig_code = expanded['mig_code'] = os.path.abspath(os.path.join(
             cmd_grpar_dir, 'mig'))
-    if mig_state is keyword_auto:
+    if mig_state == keyword_auto:
         mig_state = expanded['mig_state'] = os.path.abspath(os.path.join(
             cmd_grpar_dir, 'state'))
-    if mig_certs is keyword_auto:
+    if mig_certs == keyword_auto:
         mig_certs = expanded['mig_certs'] = os.path.abspath(os.path.join(
             cmd_grpar_dir, 'certs'))