Corrected the Volume_types URI in Volume API

Modified: src/wadls/volume-api/src/volume-api.wadl
("v1/{tenant_id}/volume_types" to "v1/{tenant_id}/types")
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Fixes: bug 1071454

Change-Id: I3236130913ca09a70e9c12e178cdaee1f4b999f3
Merge "Corrected the Volume_types URI in Volume API"