Merge pull request #1018 from yanksyoon/feat/remove_application_timeout

#1018

#### Description

*<Please add why this change is needed and what it does.>*
Adds timeout parameter to `model.remove_application()`
Addresses #855 

*<Fixes: >*


#### QA Steps

*<Commands / tests / steps to run to verify that the change works:>*
```
tox -e integration -- -k test_app_remove_timeout
```

All CI tests need to pass.

*<Please note that most likely an additional test will be required by the reviewers for any change that's not a one liner to land.>*

#### Notes & Discussion

*<Additional notes for the reviewers if needed. Please delete section if not applicable.>*

juju/model.py

@@ -1000,7 +1000,15 @@ async def remove_storage(self, *storage_ids, force=False, destroy_storage=False)
         if ret.results[0].error:
             raise JujuError(ret.results[0].error.message)
 
-    async def remove_application(self, app_name, block_until_done=False, force=False, destroy_storage=False, no_wait=False):
+    async def remove_application(
+        self,
+        app_name,
+        block_until_done=False,
+        force=False,
+        destroy_storage=False,
+        no_wait=False,
+        timeout=None
+    ):
         """Removes the given application from the model.
 
         :param str app_name: Name of the application
@@ -1009,6 +1017,8 @@ async def remove_application(self, app_name, block_until_done=False, force=False
         :param bool no_wait: Rush through application removal without waiting for each individual step to complete (=false)
         :param bool block_until_done: Ensure the app is removed from the
         model when returned
+        :param int timeout: Raise asyncio.exceptions.TimeoutError if the application is not removed
+        within the timeout period.
         """
         if app_name not in self.applications:
             raise JujuError("Given application doesn't seem to appear in the\
@@ -1019,7 +1029,7 @@ async def remove_application(self, app_name, block_until_done=False, force=False
                                                  no_wait=no_wait,
                                                  )
         if block_until_done:
-            await self.block_until(lambda: app_name not in self.applications)
+            await self.block_until(lambda: app_name not in self.applications, timeout=timeout)
 
     async def block_until(self, *conditions, timeout=None, wait_period=0.5):
         """Return only after all conditions are true.

tests/integration/test_application.py

@@ -3,6 +3,7 @@
 
 import logging
 from pathlib import Path
+import asyncio
 
 import pytest
 
@@ -326,6 +327,16 @@ async def test_app_remove_wait_flag():
         assert a_name not in model.applications
 
 
+@base.bootstrapped
+async def test_app_remove_timeout():
+    async with base.CleanModel() as model:
+        app = await model.deploy('juju-qa-test')
+        await model.wait_for_idle(status="active")
+
+        with pytest.raises(asyncio.TimeoutError):
+            await model.remove_application(app.name, block_until_done=True, timeout=1)
+
+
 @base.bootstrapped
 async def test_app_charm_name():
     async with base.CleanModel() as model: