chore: remove unused component (#730)

* chore: remove unused component

Closes #725

* chore: remove test and export Oo'

Author: machour

__tests__/tests/components/RepositorySectionTitle.js

@@ -19,7 +19,6 @@ export * from './notification-list-item.component';
 export * from './parallax-scroll.component';
 export * from './repository-list-item.component';
 export * from './repository-profile.component';
-export * from './repository-section-title.component';
 export * from './search-bar.component'; // eslint-disable-line import/no-unresolved
 export * from './section-list.component';
 export * from './state-badge.component';