Update traefik dependencies (docker/docker and related) (#1823)

Update traefik dependencies (docker/docker and related)

- Update dependencies
- Fix compilation problems
- Remove vdemeester/docker-events (in docker api now)
- Remove `integration/vendor`
- Use `testImport`
- update some deps.
- regenerate the lock from scratch (after a `glide cc`)

vendor/github.com/spf13/pflag/uint16.go

@@ -1,6 +1,9 @@
 package pflag
 
-import "strconv"
+import (
+	"fmt"
+	"strconv"
+)
 
 // -- uint16 value
 type uint16Value uint16
@@ -9,7 +12,7 @@ func newUint16Value(val uint16, p *uint16) *uint16Value {
 	*p = val
 	return (*uint16Value)(p)
 }
-
+func (i *uint16Value) String() string { return fmt.Sprintf("%d", *i) }
 func (i *uint16Value) Set(s string) error {
 	v, err := strconv.ParseUint(s, 0, 16)
 	*i = uint16Value(v)
@@ -20,8 +23,6 @@ func (i *uint16Value) Type() string {
 	return "uint16"
 }
 
-func (i *uint16Value) String() string { return strconv.FormatUint(uint64(*i), 10) }
-
 func uint16Conv(sval string) (interface{}, error) {
 	v, err := strconv.ParseUint(sval, 0, 16)
 	if err != nil {