Change TeamCity test matrix and drop appveyor/travis-ci configurations (#2315)

* TeamCity: change test matrix and test scripts

Changes test matrix to test:

* 1.13 through 1.16 on linux/amd64
* 1.15, 1.16 on windows/amd64
* 1.15 on linux/386

Also includes tests on go-tip for windows/amd64 and linux/amd64
(currently disabled, but can be turned on in a PR).

Changes test scripts to automatically select the latest patch version
of Go.

* CI: remove Travis-CI and Appveyor configuration

_scripts/gen-travis.go

@@ -55,87 +55,12 @@ func main() {
 		}
 	}
 
-	travisfh, err := os.Create(".travis.yml")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "could not create .travis.yml: %v")
-		os.Exit(1)
-	}
-
-	out := bufio.NewWriter(travisfh)
-	err = template.Must(template.New("travis.yml").Parse(`language: go
-sudo: required
-go_import_path: github.com/go-delve/delve
-
-os:
-  - linux
-
-arch:
-  - amd64
-  - arm64
-
-go:
-  - {{index .GoVersions 0}}
-  - tip
-
-matrix:
-  allow_failures:
-    - go: tip
-  exclude:
-    - arch: arm64
-      go: tip
-
-before_install:
-  - export GOFLAGS=-mod=vendor
-  - if [ $TRAVIS_OS_NAME = "linux" ]; then sudo apt-get -qq update; sudo apt-get install -y dwz; echo "dwz version $(dwz --version)"; fi
-
-
-# 386 linux
-jobs:
-  include:
-    -  os: linux
-       services: docker
-       env: go_32_version={{index .GoVersions 0}}.2 # Linux/i386 tests will fail on go1.15 prior to 1.15.2 (see issue #2134)
-
-script: >-
-    if [ $TRAVIS_OS_NAME = "linux" ] && [ $go_32_version ]; then
-      docker pull i386/centos:7;
-      docker run \
-      -v $(pwd):/delve \
-      --env TRAVIS=true \
-      --env CI=true \
-      --privileged i386/centos:7 \
-      /bin/bash -c "set -x && \
-           cd delve && \
-           yum -y update && yum -y upgrade && \
-           yum -y install wget make git gcc && \
-           wget -q https://dl.google.com/go/go${go_32_version}.linux-386.tar.gz && \
-           tar -C /usr/local -xzf go${go_32_version}.linux-386.tar.gz && \
-           export PATH=$PATH:/usr/local/go/bin && \
-           go version && \
-           uname -a && \
-           make test";
-    else
-      make test;
-    fi
-  
-cache:
-  directories:
-    - $HOME/AppData/Local/Temp/chocolatey
-`)).Execute(out, args)
-
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Error executing template: %v", err)
-		os.Exit(1)
-	}
-	_ = out.Flush()
-	_ = travisfh.Close()
-
 	githubfh, err := os.Create(".github/workflows/test.yml")
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Could not create .github/test.yml: %v", err)
 		os.Exit(1)
 	}
-	out = bufio.NewWriter(githubfh)
+	out := bufio.NewWriter(githubfh)
 	err = template.Must(template.New(".github/workflows/test.yml").Parse(`name: Delve CI
 
 on: [push, pull_request]