Add coverage (goveralls) github action (#2263)

- Removes outdated Travis CI configuration and associated scripts
- Adds a new GitHub Actions workflow for coverage reporting
- Simplifies coverage collection by using native Go tooling instead of
custom bash scripts

Author: abhinavdangeti

.github/workflows/cover.yml

@@ -0,0 +1,30 @@
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+name: Coverage
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.x'
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Clean environment
+        run: |
+          go clean -cache -testcache -modcache
+          rm -f profile.cov
+      - name: Test
+        run: |
+          go test -coverprofile=profile.cov ./...
+      - name: Remove non-GO entries from coverage profile
+        run: |
+          grep -E 'mode|\.go' profile.cov > profile_go.cov
+      - name: Send coverage
+        uses: shogo82148/actions-goveralls@v1
+        with:
+          path-to-profile: profile_go.cov

.travis.yml

@@ -1,7 +1,7 @@
 # ![bleve](docs/bleve.png) bleve
 
 [![Tests](https://github.com/blevesearch/bleve/actions/workflows/tests.yml/badge.svg?branch=master&event=push)](https://github.com/blevesearch/bleve/actions/workflows/tests.yml?query=event%3Apush+branch%3Amaster)
-[![Coverage Status](https://coveralls.io/repos/github/blevesearch/bleve/badge.svg?branch=master)](https://coveralls.io/github/blevesearch/bleve?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/blevesearch/bleve/badge.svg)](https://coveralls.io/github/blevesearch/bleve)
 [![Go Reference](https://pkg.go.dev/badge/github.com/blevesearch/bleve/v2.svg)](https://pkg.go.dev/github.com/blevesearch/bleve/v2)
 [![Join the chat](https://badges.gitter.im/join_chat.svg)](https://app.gitter.im/#/room/#blevesearch_bleve:gitter.im)
 [![Go Report Card](https://goreportcard.com/badge/github.com/blevesearch/bleve/v2)](https://goreportcard.com/report/github.com/blevesearch/bleve/v2)