Fixed importing concurrent

[Tom-Kingstone]

NOTE: Depends on

Issues addressed by this PR

Closes #248

As in issue

Test files

The LBT beta test script will be the test - ensure that the Solar.png file is created in the same directory as the grasshopper script.

Changelog

Additional comments

[Felix-Mallinder]

Tested. Can confirm success as solar.png is created in the same folder as gh test script.

[Tom-Kingstone]

@BHoMBot check core
@BHoMBot check compliance

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check core
• check code-compliance
• check documentation-compliance
• check project-compliance
• check branch-compliance
• check dataset-compliance
• check copyright-compliance

[Tom-Kingstone]

@BHoMBot check versioning
@BHoMBot check installer

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check versioning
• check installer

[Felix-Mallinder]

Tested. Can confirm success as solar.png is created in the same folder as gh test script.

[Tom-Kingstone]

@BHoMBot check unit-tests
@BHoMBot check serialisation
@BHoMBot check null-handling

[bhombot-ci]

@Tom-Kingstone to confirm, the following actions are now queued:

• check unit-tests
• check serialisation
• check null-handling

[jamesramsden-bh]

solar.png created successfully. Code reviewed, reference change is fine.

[jamesramsden-bh]

@BHoMBot check ready-to-merge

[bhombot-ci]

@jamesramsden-bh to confirm, the following actions are now queued:

• check ready-to-merge