Improve some frequently failing tests

Author: krassowski

atest/03_Notebook.robot

@@ -68,5 +68,6 @@ Code Overrides
     Setup Notebook    Python    ${file}
     ${virtual_path} =    Set Variable    ${VIRTUALDOCS DIR}${/}Code overrides.ipynb
     Wait Until Created    ${virtual_path}
+    Wait Until Keyword Succeeds    10x    1s    File Should Not Be Empty    ${virtual_path}
     ${document} =    Get File    ${virtual_path}
     Should Be Equal    ${document}    get_ipython().run_line_magic("ls", "")\n\n\nget_ipython().run_line_magic("pip", " freeze")\n

atest/05_Features/Highlights.robot

@@ -45,14 +45,15 @@ Highlights are modified after typing
     Should Highlight Token    testa
 
 Highlights are removed when no cell is focused
-    Enter Cell Editor    1    line=2
     # Remove when turned on
     Configure JupyterLab Plugin    {"removeOnBlur": true}    plugin id=${HIGHLIGHTS PLUGIN ID}
+    Enter Cell Editor    1    line=2
     Should Highlight Token    test
     Blur Cell Editor    1
     Should Not Highlight Any Tokens
     # Do not remove when turned off
     Configure JupyterLab Plugin    {"removeOnBlur": false}    plugin id=${HIGHLIGHTS PLUGIN ID}
+    Enter Cell Editor    1    line=2
     Should Highlight Token    test
     Blur Cell Editor    1
     Should Highlight Token    test

atest/05_Features/Jump.robot

@@ -16,6 +16,7 @@ Python Jumps between Files
     Jump To Definition    ${sel}
     Wait Until Page Contains    ANOTHER_CONSTANT
     Capture Page Screenshot    10-jumped.png
+    Clean Up After Working With File    jump_b.py
 
 Ctrl Click And Jumping Back Works
     [Setup]    Prepare File for Editing    Python    editor    jump.py