chore: update changelog format (#47)

Author: sindharta

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## [0.0.2-preview.2] - 2020-3-5
+## [0.0.2-preview.2] - 2020-03-05
 
 * feat: Fader imporvements. Reverse FadeOut and FadeIn, and a color to highlight FaderPlayableAsset
 * fix: reverse the parameter to copy images to StreamingAssets
@@ -9,7 +9,7 @@
 * fix: Support folder D&D for StreamingImageSequencePlayableAsset from folders which are not under "StreamingAssets"
 * fix: Test assembly definitions.
 
-## [0.0.2-preview.1] - 2020-3-2
+## [0.0.2-preview.1] - 2020-03-02
 
 - Renaming to *Streaming Image Sequence \<com.unity.streaming-image-sequence\>*.
 - feat: folder drag and drop support.