Update minimum supported go version to 1.11

Add support for go 1.13

seprate out the flags to individual files

fix md2man dependency issue

.travis.yml

@@ -3,9 +3,9 @@ sudo: false
 dist: trusty
 osx_image: xcode8.3
 go:
-  - 1.10.x
   - 1.11.x
   - 1.12.x
+  - 1.13.x
 
 os:
   - linux
@@ -16,16 +16,11 @@ cache:
     - node_modules
 
 before_script:
-  - go get github.com/shurcooL/vfsgen || true
-  - go get github.com/shurcooL/httpfs/union || true
   - go get github.com/urfave/gfmrun/... || true
   - go get golang.org/x/tools/cmd/goimports
-  - if [ ! -f node_modules/.bin/markdown-toc ] ; then
-      npm install markdown-toc ;
-    fi
+  - npm install markdown-toc ;
 
 script:
-  - go run build.go generate
   - go run build.go vet
   - go run build.go test
   - go run build.go gfmrun

docs.go

@@ -3,12 +3,11 @@ package cli
 import (
 	"bytes"
 	"fmt"
+	"github.com/cpuguy83/go-md2man/v2/md2man"
 	"io"
 	"sort"
 	"strings"
 	"text/template"
-
-	"github.com/cpuguy83/go-md2man/md2man"
 )
 
 // ToMarkdown creates a markdown string for the `*App`