Fixes and updates in demo apps for new themes, dependency updates, and bump to 1.7.0

Author: darrenburns

poetry.lock

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "textual-dev"
-version = "1.6.0"
+version = "1.7.0"
 homepage = "https://github.com/Textualize/textual-dev"
 description = "Development tools for working with Textual"
 authors = [
@@ -27,7 +27,7 @@ include = ["src/textual_dev/py.typed", { path = "tests", format = "sdist" }]
 
 [tool.poetry.dependencies]
 python = "^3.8.1"
-textual = ">=0.86.0"
+textual = ">=0.86.2"
 textual_serve = ">=1.0.3"
 aiohttp = ">=3.8.1"
 click = ">=8.1.2"
@@ -56,9 +56,6 @@ textual = "textual_dev.cli:run"
 asyncio_mode = "auto"
 testpaths = ["tests"]
 addopts = "--strict-markers"
-markers = [
-    "integration_test: marks tests as slow integration tests (deselect with '-m \"not integration_test\"')",
-]
 
 [tool.mypy]
 implicit_reexport = false