Be cleverer about unreleased doc versions

_data/python-versions.json

@@ -1,4 +1,4 @@
 [
-  {"version":"0.18.1","title":"0.18.1","aliases":["latest"]},
-  {"version":"0.18.0","title":"0.18.0","aliases":}
+  {"version":"0.18.1","title":"0.18.1","aliases":[]},
+  {"version":"0.18.0","title":"0.18.0","aliases":["latest"]}
 ]

implementations/python/update-doc-versions.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+latestversion=$(git tag | fgrep python-preserves@ | cut -d@ -f2 | sort -V -r | head -1)
 (
     firstitem='y';
     printf '[';
@@ -7,10 +8,14 @@
         if [ "$firstitem" = "y" ]
         then
             firstitem=n
-            aliases='["latest"]'
         else
             printf ','
-            aliases=''
+        fi
+        if [ "$version" = "$latestversion" ]
+        then
+            aliases='["latest"]'
+        else
+            aliases='[]'
         fi
         printf '\n  {"version":"%s","title":"%s","aliases":%s}' "$version" "$version" "$aliases"
     done;