Deps need upgrading

[joe-getcouragenow]

I needed to upgrade oto for MAC, and then noticed all needed to be.

The tests all pass with a go.mod of:

module github.com/faiface/beep

go 1.14

require (
	github.com/gdamore/tcell v1.3.0
	github.com/gopherjs/gopherwasm v1.0.0 // indirect
	github.com/hajimehoshi/go-mp3 v0.3.0
	github.com/hajimehoshi/oto v0.6.1
	github.com/jfreymuth/oggvorbis v1.0.1
	github.com/jfreymuth/vorbis v1.0.0 // indirect
	github.com/mewkiz/flac v1.0.6
	github.com/pkg/errors v0.9.1
	gopkg.in/DATA-DOG/go-sqlmock.v1 v1.3.0 // indirect
)

How about upgrading ??

[makew0rld]

This was fixed by #95 and is in the master branch. Maybe better to install that directly with go get.