fix code quality problems

[kamilsk]

cmd/retry/main.go:116:14:warning: error return value not checked (spin.Color("red")) (errcheck)
cmd/retry/main.go:117:37:warning: error return value not checked (color.New(color.FgYellow).Fprintf(stderr, "#%d attempt at %s... \n", attempt+1, time.Now().Sub(start))) (errcheck)
cmd/retry/main.go:119::warning: Subprocess launching with variable.,HIGH,HIGH (gas)
cmd/retry/main.go:67:34:warning: error return value not checked (color.New(color.FgRed).Fprintf(app.Stderr, format, err)) (errcheck)
cmd/retry/main.go:88:39:warning: error return value not checked (color.New(color.FgYellow).Fprintln(stderr, "notify component is not ready yet")) (errcheck)
cmd/retry/main.go:90:18:warning: error return value not checked (report.Execute(app.Stdout, struct {) (errcheck)
cmd/retry/parser_test.go:13::warning: cyclomatic complexity 11 of function Test_parse() is high (> 10) (gocyclo)

[kamilsk]

also fix

$ make test
go list ./... | grep -v vendor | grep -v ^_ | xargs go test -race 
==================
WARNING: DATA RACE
Read at 0x00c420088540 by goroutine 59:
  github.com/kamilsk/retry_test.Example_httpClient.func1()
      /Users/kamilsamigullin/Development/go/src/github.com/kamilsk/retry/example_http_client_test.go:43 +0x4d
  net/http.HandlerFunc.ServeHTTP()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:1918 +0x51
  net/http.serverHandler.ServeHTTP()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:2619 +0xbc
  net/http.(*conn).serve()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:1801 +0x83b

Previous write at 0x00c420088540 by goroutine 54:
  github.com/kamilsk/retry_test.Example_httpClient.func1()
      /Users/kamilsamigullin/Development/go/src/github.com/kamilsk/retry/example_http_client_test.go:47 +0xe2
  net/http.HandlerFunc.ServeHTTP()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:1918 +0x51
  net/http.serverHandler.ServeHTTP()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:2619 +0xbc
  net/http.(*conn).serve()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:1801 +0x83b

Goroutine 59 (running) created at:
  net/http.(*Server).Serve()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:2720 +0x37c
  net/http/httptest.(*Server).goServe.func1()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/httptest/server.go:280 +0xa2

Goroutine 54 (running) created at:
  net/http.(*Server).Serve()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/server.go:2720 +0x37c
  net/http/httptest.(*Server).goServe.func1()
      /usr/local/Cellar/go/1.9.2/libexec/src/net/http/httptest/server.go:280 +0xa2
==================
FAIL
FAIL    github.com/kamilsk/retry        0.678s
ok      github.com/kamilsk/retry/backoff        1.030s
ok      github.com/kamilsk/retry/classifier     1.024s
ok      github.com/kamilsk/retry/cmd/retry      1.050s
ok      github.com/kamilsk/retry/jitter 1.027s
ok      github.com/kamilsk/retry/strategy       1.191s
make: *** [test] Error 1

[kamilsk]

fixed