Currently there's no method to find the mod version from within the game. This is sad.
Suggestion: do as CBA does.
In CBA-style projects,version info is put into the CfgPatches >> _addon class
For example:
class CfgPatches { class MyMod { version = 3.15; versionAr[] = {3,15,3,210310}; versionStr = "3.15.3.210310"; }; };