Resolve "Migrate '.fa-spinner' to '.spinner' within 'app/views/projects/cycle_analytics'"

What does this MR do?

The old font awesome .fa-spinner class begun being migrated to our own .spinner class early in 2019.

The directory mentioned in this issue's title still makes use of .fa-spinner by calling a variation of icon("spinner and needs to be migrated. This needs to happen in order to provide a consistent user experience.

If any problems are encountered while performing the migration, please raise them on the associated epic.

Screenshots

Before	After
Screen_Recording_2020-02-11_at_14.42.40	Screen_Recording_2020-02-11_at_14.42.16

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team

Related issue

#204740 (closed)