split dockerfile into base image and CI image (#2066)

* split dockerfile into base image and CI

* doesn't exist yet

* fix path

* cache on this branch

* latest

* use cache

* don't double pull
old-commit-hash: a3f5643019

.dockerignore

@@ -1,5 +1,21 @@
 .git
 .DS_Store
+*.dylib
+*.DSYM
+*.d
+*.pyc
+*.pyo
+.*.swp
+.*.swo
+.*.un~
+*.tmp
+*.o
+*.o-*
+*.os
+*.os-*
+*.so
+*.a
+
 notebooks
 phone
 massivemap