[API Bundle] Remove require fixtures-bundle from composer.

| Q	                       | A     |
|--------------------------|------ |
| Bug Fix?        	| y     |
| New Feature?	| n     |
| BC Breaks?	       | n     |
| Deprecations?	| n     |
| Tests Pass?	       | n     |
| Fixed Tickets	       | #2112  |
| License	               | MIT |
| Doc PR                  |        |