feat(es8): support elasticsearch v8 (#546)

add support elasticsearch v8

BREAKING CHANGE: Pelias no longer supports elasticsearch v6

This change drops support for elasticsearch v6 in order to support v8.
The current recommended version remains v7.

bin/units

@@ -2,4 +2,12 @@
 
 set -euo pipefail
 
+# ignore any user configuration in tests
+echo '{}' > /tmp/__pelias.json
+export PELIAS_CONFIG=/tmp/__pelias.json
+function cleanup {
+  rm -f /tmp/__pelias.json
+}
+trap cleanup EXIT
+
 node test/test.js | npx tap-dot

package.json

@@ -34,10 +34,10 @@
     "iso3166-1": "^0.5.0",
     "lodash": "^4.5.1",
     "pelias-blacklist-stream": "^1.0.0",
-    "pelias-config": "^4.10.0",
-    "pelias-dbclient": "^2.13.0",
+    "pelias-config": "^6.0.0",
+    "pelias-dbclient": "^3.0.0",
     "pelias-logger": "^1.2.1",
-    "pelias-model": "^9.1.1",
+    "pelias-model": "^10.0.0",
     "through2": "^3.0.0",
     "through2-filter": "^3.0.0",
     "through2-map": "^3.0.0",