update tephra version to 0.6.0, remove snapshot dependency
update tephra version to 0.6.0, remove snapshot dependency

caskdata/cdap,caskdata/cdap,mpouttuclarke/cdap,hsaputra/cdap,anthcp/cdap,mpouttuclarke/cdap,anthcp/cdap,anthcp/cdap,mpouttuclarke/cdap,anthcp/cdap,caskdata/cdap,chtyim/cdap,anthcp/cdap,hsaputra/cdap,hsaputra/cdap,mpouttuclarke/cdap,caskdata/cdap,chtyim/cdap,chtyim/cdap,caskdata/cdap,chtyim/cdap,caskdata/cdap,hsaputra/cdap,chtyim/cdap,chtyim/cdap,mpouttuclarke/cdap,hsaputra/cdap