test: update coverage folders

jest.config.ts

@@ -15,6 +15,7 @@ const projects: any = fs
 export default async (): Promise<Config.InitialOptions> => ({
     projects,
     verbose: true,
+    coverageDirectory: "./coverage/js",
     collectCoverageFrom: ["<rootDir>/src/**/*.ts", "!<rootDir>/src/**/index.ts", "!<rootDir>/src/**/*.d.ts"],
     coverageThreshold: {
         global: {

packages/incremental-merkle-tree.sol/.solcover.js

@@ -0,0 +1,3 @@
+module.exports = {
+    istanbulFolder: "../../coverage/sol"
+}