community announcement via community factory contract (#79)

It works on manual testing on testnet.

Basically this pr
- add a simple community factory and a community contract.
- in create_community, create foo.communities.devhub.near account, add
access key, deploy contract, grant social db access to devhub.near
- in update_community, call social.near to update profile name and image
is updated
- in delete community, call foo.communities.devhub.near to self destroy

TODO:
- [x] add back community_addon and update_community test as workspace
test because unit test no longer work due to cross contract call in
create_community
- [x] add workspace tests for this PR
- [ ] (**After this PR approved**) manual deploy community factory to
community.devhub.near and manual call create_community_account for
existing communities.

Note: doing migration and self-upgrade community factory similar to main
contract should work, but I think it doesn't worth the effort:
- These contracts are unlikely need to be changed it has granted full
social db write access to devhub.near.
- And it's also not a real migration: we can add create factory account,
deploy factory contract and create_community_accounts as a migration,
but it doesn't actually migrate any state.
- Self-upgrade needs more thought. Most of time factory contract is not
changed, we should detect this to prevent unnecessary self upgrade on
every commit. We'll also need to all update community contracts that
deployed by the factory contract, but factory contract doesn't keep
track of that, only devhub contract does. So this has to be implement on
devhub contract and considering gas limit. It will be much easier to
upgrade with a client side script.

.github/workflows/main.yml

@@ -19,6 +19,12 @@ jobs:
           default: true
       - uses: Swatinem/rust-cache@v1
       - run: rustup target add wasm32-unknown-unknown
+      - name: Build community contract
+        run: cd community && ./build.sh
+      - name: Build community factory contract
+        run: cd community-factory && ./build.sh
+      - name: Build devhub contract
+        run: ./build.sh
       - name: Unit tests
         run: |
-          cargo test
+          cargo test

.github/workflows/release.yml

@@ -24,7 +24,11 @@ jobs:
         default: true
     - uses: Swatinem/rust-cache@v1
     - run: rustup target add wasm32-unknown-unknown
-    - name: Build contract
+    - name: Build community contract
+      run: cd community && ./build.sh
+    - name: Build community factory contract
+      run: cd community-factory && ./build.sh
+    - name: Build devhub contract
       run: ./build.sh
     - name: Install near CLI
       run: |