Disable MBT tests if the "mocks" feature is not enabled (informalsyst…

…ems#643)

* Add structure to MBT

* Only run model_based test if mocks feature is enabled

* Remove model_based test from the executor

* update CHANGELOG

CHANGELOG.md

@@ -29,13 +29,14 @@
 ### BUG FIXES
 
 - [ibc]
-  - [nothing yet]
+  - Fix panic in conn open try when no connection id is provided ([#626])
+  - Disable MBT tests if the "mocks" feature is not enabled ([#643])
 
 - [ibc-relayer]
   - [nothing yet]
 
 - [ibc-relayer-cli]
-  - [nothing yet]
+  - Fix wrong acks sent with `tx raw packet-ack` in a 3-chain setup ([#614])
 
 ### BREAKING CHANGES
 
@@ -49,23 +50,12 @@
 - [ibc-relayer-cli]
   - [nothing yet]
 
-### BUG FIXES
-
-- [ibc]
-  - Fix panic in conn open try when no connection id is provided ([#626])
-
-- [ibc-relayer]
-  - [nothing yet]
-
-- [ibc-relayer-cli]
-  - Fix wrong acks sent with `tx raw packet-ack` in a 3-chain setup ([#614])
-
-
 [#316]: https://github.com/informalsystems/ibc-rs/issues/316
 [#560]: https://github.com/informalsystems/ibc-rs/issues/560
 [#614]: https://github.com/informalsystems/ibc-rs/issues/614
 [#624]: https://github.com/informalsystems/ibc-rs/issues/624
 [#626]: https://github.com/informalsystems/ibc-rs/issues/626
+[#643]: https://github.com/informalsystems/ibc-rs/issues/643
 
 ## v0.1.0
 *February 4, 2021*