Add dill to main dependencies (#1886)

* Add `dill` to main dependencies

`dill` is imported by `sdk/python/feast/on_demand_feature_view.py` and
so is needed as a main dependency.

Signed-off-by: Judah Rand <17158624+judahrand@users.noreply.github.com>

* Relax `dill` version constraint

Signed-off-by: Judah Rand <17158624+judahrand@users.noreply.github.com>

sdk/python/setup.py

@@ -42,6 +42,7 @@
 REQUIRED = [
     "Click==7.*",
     "colorama>=0.3.9",
+    "dill==0.3.*",
     "fastavro>=1.1.0",
     "google-api-core>=1.23.0",
     "googleapis-common-protos==1.52.*",
@@ -116,7 +117,6 @@
     "google-cloud-core==1.4.*",
     "redis-py-cluster==2.1.2",
     "boto3==1.17.*",
-    "dill==0.3.0"
 ]
 
 # Get git repo root directory