* 1. Fixed improper spacing between captions while converting TTML -> VTT
2. Added String To Pointer utility.
3. Converted TTML style attributes to pointers
4. Fixed Webvtt not using parent style attributes in region
* 1. Fixed Test cases
2. Fixed SRT and STL strings join
* 1. Removed Util
2. Added Regex to remove multiple space
3. In ttml.go update 'getStyleAttributes()' to 'newStyleAttributesFromTTMLInStyleAttributes()'
4. Using go-astikit to convert string to string pointer.
* Improper spacing fix
* Improper spacing fix
* Added Space in TTML out.
Added comments
* Added space to fix unit test
* update go.sum
* update go.sum
* Update go.sum
* Update go.sum
