CodeChecker store fails (sqlite)
Git tag information    : 6.0.1-8-ga3d8f81   
I am using sqlite. My system: Ubuntu 17.04

I ran the command:
`CodeChecker check -b "make clean;make" -o "/home/peters/codechecker_results"`
which worked fine. At least some .plist files two .json and one .json.lock file have been created in the directory ~/codechecker_results

Then I tried:
`CodeChecker store /home/peters/codechecker_results/ -n test`
which failed with the following error message:
`[13:25] - Storing analysis results for run 'test'`
`[13:25] - Storage failed: 'unicode' does not have the buffer interface`

I executed the store-command with the verbose debug option turned on, which then returns the following log messages:
[store.log](https://github.com/Ericsson/codechecker/files/1362532/store.log)

diff --git a/libcodechecker/libhandlers/store.py b/libcodechecker/libhandlers/store.py
index ab7f45a4..40faea33 100644
--- a/libcodechecker/libhandlers/store.py
+++ b/libcodechecker/libhandlers/store.py
@@ -322,7 +322,7 @@ def main(args):
 
         client.massStoreRun(args.name,
                             args.tag if 'tag' in args else None,
-                            context.version,
+                            str(context.version),
                             b64zip,
                             'force' in args)
 
['libcodechecker/libhandlers/store.py']