Instructor selection: Breaks between events in admin view

[maneesha]

In the admin view, the breaks between each event listings are thin gray lines. Consider what we can do to make the breaks more prominent (darker/heavier break lines; more prominent headers, etc)

[pbanaszkiewicz]

This is how it looks without horizontal line and with slightly bigger vertical spacing between entries:

This is how it looks without horizontal line and with 100px vertical spacing between entries: (Spacing between header 'Recruitment processes' and the first entry can be reduced)

This is how it looks with darker (about 3 times darker) horizontal line:

This is how it looks with darker (3 times darker) horizontal line and increased spacing (same spacing as in first screenshot):

Finally this is how it looks with default horizontal line and slightly bigger spacing: (This is the closest to current look)

[maneesha]

Moving this from the instructor selection project to the accessibility/UI project.