Merge #16243: doc: Remove travis badge from readme

e91f0a7af2 doc: Remove travis badge from readme (MarcoFalke)

Pull request description:

  The readme(s) are shipped in the released source-code archive, in which case the travis badge is useless since it doesn't link to the travis result of the correct commit/tag/branch. GitHub embeds the correct links for each tag or commit that ci ran on, so we don't need this link in the readme.

ACKs for commit e91f0a:
  hebasto:
    ACK e91f0a7af2

Tree-SHA512: 860435a58b38a9bd0bc62a1e74b3a63c138c9a2f09008a090d5ecc7fd86fa908d2e5eda41d16606507a238d9488fa5323405364a9556b670684a2e4838aead2d

README.md

@@ -1,8 +1,6 @@
 Bitcoin Core integration/staging tree
 =====================================
 
-[![Build Status](https://travis-ci.org/bitcoin/bitcoin.svg?branch=master)](https://travis-ci.org/bitcoin/bitcoin)
-
 https://bitcoincore.org
 
 What is Bitcoin?

test/README.md

@@ -13,8 +13,7 @@ bitcoin-tx.
 - [lint](/test/lint/) which perform various static analysis checks.
 
 The util tests are run as part of `make check` target. The functional
-tests and lint scripts are run by the travis continuous build process whenever a pull
-request is opened. All sets of tests can also be run locally.
+tests and lint scripts can be run as explained in the sections below.
 
 # Running tests locally
 

test/functional/test_runner.py

@@ -67,14 +67,14 @@ TEST_EXIT_PASSED = 0
 TEST_EXIT_SKIPPED = 77
 
 EXTENDED_SCRIPTS = [
-    # These tests are not run by the travis build process.
+    # These tests are not run by default.
     # Longest test should go first, to favor running tests in parallel
     'feature_pruning.py',
     'feature_dbcrash.py',
 ]
 
 BASE_SCRIPTS = [
-    # Scripts that are run by the travis build process.
+    # Scripts that are run by default.
     # Longest test should go first, to favor running tests in parallel
     'feature_fee_estimation.py',
     'wallet_hd.py',
@@ -495,7 +495,8 @@ class TestHandler:
             for job in self.jobs:
                 (name, start_time, proc, testdir, log_out, log_err) = job
                 if int(time.time() - start_time) > self.timeout_duration:
-                    # In travis, timeout individual tests (to stop tests hanging and not providing useful output).
+                    # Timeout individual tests if timeout is specified (to stop
+                    # tests hanging and not providing useful output).
                     proc.send_signal(signal.SIGINT)
                 if proc.poll() is not None:
                     log_out.seek(0), log_err.seek(0)
@@ -583,7 +584,7 @@ def check_script_list(*, src_dir, fail_on_warn):
     if len(missed_tests) != 0:
         print("%sWARNING!%s The following scripts are not being run: %s. Check the test lists in test_runner.py." % (BOLD[1], BOLD[0], str(missed_tests)))
         if fail_on_warn:
-            # On travis this warning is an error to prevent merging incomplete commits into master
+            # On CI this warning is an error to prevent merging incomplete commits into master
             sys.exit(1)