Lower jest threshold - allow error handling

\### Rationale
100% thresholds across code is unreasonable when there should be some
error handling within the plugin. This is so when eslint changes its
interpretation of syntax or a user provides something weird/unexpected
the plugin doesn't cause `eslint` to crash.

Author: codejedi365

jest.config.js

@@ -4,10 +4,10 @@ module.exports = {
   preset: "ts-jest", 
   coverageThreshold: {
     global: {
-      branches: 100,
+      branches: 90,
       functions: 100,
-      lines: 100,
-      statements: 100
+      lines: 90,
+      statements: 90
     }
   },
   testPathIgnorePatterns: ["<rootDir>/tests/fixtures/"],