[dev] Update beat packages version

- beat.core to 1.10.3
- beat.backend.python to 1.7.6
- beat.cmdline to 1.7.0

dev.yml

@@ -11,9 +11,9 @@ dependencies:
   - beat-devel=2020.01.09
 
   # beat dependencies matching release.cfg
-  - beat.core=1.9.2
-  - beat.backend.python=1.7.3
-  - beat.cmdline=1.6.1
+  - beat.core=1.10.3
+  - beat.backend.python=1.7.6
+  - beat.cmdline=1.7.1
 
   # requirements.txt, they are indirectly pinned through the above
   - docopt