Clash of clans developer Supercell released in their blog that there will be a balancing patch in August.
Read the full update note below
•Cannon damage increased for levels 11-14
We currently are developing a better defensive answer to mass-attacks of mid-size units. For now, a Cannondamage boost will help pick up the slack.
•Healers trigger air traps (once again)
Healers have become a staple high-level troop, but stay out of defensive range too safely, sometimes for the entire battle. Cue the Seeking Air Mines!
•Miner movement speed reduced
Miners are a bit too speedy for a unit that burrows underground, making them too effective at overwhelming and wiping out entire Villages.
•Attackers can deploy more of their army before Eagle Artillery will activate
Eagle Artillery's quick activation limits phase-based attacks more than it needs to. This change gives attackers more early battle flexibility.