Dot using api (#75)

* wip

* DOT service using kiln API

* bump version to 2.5.4

Author: nooxx

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kilnfi/sdk",
-  "version": "2.5.3",
+  "version": "2.5.4",
   "autor": "Kiln <[email protected]> (https://kiln.fi)",
   "license": "BUSL-1.1",
   "description": "JavaScript sdk for Kiln API",
@@ -30,8 +30,8 @@
     "@blockfrost/blockfrost-js": "^5.0.0",
     "@cosmjs/proto-signing": "^0.30.0",
     "@cosmjs/stargate": "^0.30.0",
-    "@polkadot/api": "^10.4.1",
     "@solana/web3.js": "^1.47.3",
+    "@substrate/txwrapper-polkadot": "^7.0.1",
     "@taquito/rpc": "^16.0.1",
     "axios": "^0.23.0",
     "ethers": "^5.6.4",