rolls should be fixed length

[pzhang87]

When reporting a bug/issue:

• Fantasy Crescendo Version: v0.3.0-alpha
• Operating System: Windows 10
• Expected Behavior: After shielding, a character's roll should force movement of a fixed length.
• Actual Behavior: Character can roll a variable distance based on how long the directional input is held on controller.
• Steps to reproduce the behavior:
  0. With Youmu, while holding shield, press/hold a horizontal directional input on controller. The length of roll appears to correspond to how long the input is held.

[james7132]

This should be fixed as of 85cb16186519024bcae553aa3989b793e1b65499