v0.7.6

Bugfix

• Fixes the default value of energy_thres in experimental.rt60 to match the
  previous behavior of the function (issue #358)
• Further fixes issue with cast reflections delays to float32 in room.py (#353)
  which was not fully fixed by the previous update
• Fixes calls to deprecated API of scipy.linalg.eigh
• Fixes use of deprecated feature of numpy (conversion of singleton array to scalar)