"go get" installation fails: invalid character U+007E

**Describe the bug**
Trying to run `go get github.com/jesseduffield/lazydocker`, but it fails with these error messages:

```
# github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:13:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:13:7: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:20:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:20:8: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:27:9: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:34:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:34:11: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:41:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:41:13: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:49:10: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:49:10: too many errors
```

**To Reproduce**
Steps to reproduce the behavior:
1. Use golang version 1.13
2. Run `go get github.com/jesseduffield/lazydocker`
3. See error

**Expected behaviour**
The installation shouldn't fail.

**Screenshots**
Terminal output
```
~ 4s
❯ sudo apt install golang
Reading package lists... Done
Building dependency tree
Reading state information... Done
golang is already the newest version (2:1.13~1ubuntu2).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

~
❯ go get github.com/jesseduffield/lazydocker
# github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:13:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:13:7: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:20:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:20:8: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:27:9: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:34:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:34:11: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:41:2: invalid character U+007E '~'
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:41:13: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:49:10: syntax error: unexpected |, expecting semicolon or newline or }
go/src/github.com/jesseduffield/lazydocker/vendor/golang.org/x/exp/constraints/constraints.go:49:10: too many errors
```

**Desktop (please complete the following information):**
- OS: Linux Mint 20.3 (Una), based on Ubuntu 20.4 LTS
- Lazydocker Version: Latest? Whatever version I get when trying to install with Go.

**Additional context**
Have installed lazydocker this way on 3-4 computers with the same os (and I assume same Go version) without this issue.

I love lazydocker.