Add showing product update message

[sibinhho99]

Description

Allows maintainer to make product update announcements

Related Issue

#247

Motivation and Context

Prof @knmnyn's request

How Has This Been Tested?

Local testing

Screenshots (if appropriate):

Demo: https://youtu.be/DtyGSvB5m-U

The admin can set new messages or toggle the visibility of the message on/off using rake tasks

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

Closes 247.

[huyuxin0429]

Hmm does the message just stay there? How do we remove the message once we are done announcing?

[knmnyn]

Are you using Rails' flash message system? I think that feature is designed for exactly such purposes?

[sibinhho99]

Hmm does the message just stay there? How do we remove the message once we are done announcing?

Currently the message just stay there. I can add the function for maintainer to turn it on/ off

Are you using Rails' flash message system? I think that feature is designed for exactly such purposes?

Yes I am using Rails' flash message

[huyuxin0429]

Hmm does the message just stay there? How do we remove the message once we are done announcing?

Currently the message just stay there. I can add the function for maintainer to turn it on/ off

Are you using Rails' flash message system? I think that feature is designed for exactly such purposes?

Yes I am using Rails' flash message

Yeah adding a functionality to turn it on and off will be great! Please document the instructions you have provided in maybe an admin user guide.

[huyuxin0429]

Please add ability to turn the banner on/off and document steps in admin usage guide.

[sibinhho99]

Please add ability to turn the banner on/off and document steps in admin usage guide.

Done and updated PR description accordingly. New demo: https://youtu.be/DtyGSvB5m-U.

[coveralls]

coverage: 4.218% (+0.03%) from 4.189%
when pulling 3806ce1 on sibinhho99:set_product_update
into 0fb4da9 on WING-NUS:master.