Pin datacube version to latest stable release

Tisham Dhar · whatnick · commit 6b143e08b17f · 2020-09-15T12:56:19.000+10:00
diff --git a/requirements-docker.txt b/requirements-docker.txt
@@ -1,3 +1,3 @@
 --extra-index-url https://packages.dea.ga.gov.au/ --pre
 digitalearthau
-datacube>=1.8.0
+datacube==1.8.3
