DOC: Add integration tests to release guidelines

RELEASE_GUIDELINES.md

@@ -13,16 +13,19 @@ guidelines of the CaosDB Project
 
 ## Steps
 
-1. Create a release branch from the dev branch. This prevents further changes
-   to the code base and a never ending release process. Naming: `release-<VERSION>`
+1. Create a release branch from the dev branch. This prevents further changes to
+   the code base and a never ending release process. Naming:
+   `release-<VERSION>`. Also create a branch with the same name in cppinttests.
 
 2. Update CHANGELOG.md
 
 3. Check all general prerequisites.
 
 4. Update version numbers:
-   1. In [CMakeLists.txt](./CMakeLists.txt): Check the `MAJOR`, `MINOR`, `PATCH` version variables.
+   1. In [CMakeLists.txt](./CMakeLists.txt): Check the version variables and
+      make sure that the compatible caosdb-server version is set correctly.
    2. In `conanfile.py`: Update the `version` variable.
+   3. In `caosdb-cppinttest/conanfile.py`: Update the version
 
 5. Merge the release branch into the main branch.
 
@@ -37,4 +40,5 @@ guidelines of the CaosDB Project
 
 9. Release cppinttests with updated cpplib version
 
-10. Merge `main` back into `dev` and increase patch version by one to begin next release cycle.
+10. Merge `main` back into `dev` and increase patch version by one to begin next
+    release cycle. Do the same in cppintest.