Change `TimeEntry.Time` to a `float64`

I had forgotten that time spent can be a decimal. Make this field a
float and change related code accordingly:

* --time flag
* `NewTimeEntry()` `time` argument
* `buildSubmissionParams()` can't use `strconv.Itoa` as that's an
  integer function. Instead we use `FormatFloat`. Truncate time parsing
  to two decimal places because to me that seems like enough. Who's
  going to say they spent `0.324` hours on something? Also, in order to
  be able to properly submit values to TimeTask (at least on the edition
  I use), the times must be written in European/French format, with
  commas (`,`) as decimal separators. Do a string replace to get this,
  as the float formatter will give us a period (`.`) separator.

3 files changed, 7 insertions, 4 deletions

diff --git a/main.go b/main.go
index 8b3db02..e685d25 100644
--- a/main.go
+++ b/main.go
@@ -40,7 +40,7 @@ func main() {
 	time_spent := kingpin.Flag("time", "Time spent working on project.").
 		Short('t').
 		Default("7").
-		Int()
+		Float()
 	date_str := kingpin.Flag("date", "Date when work was done (e.g. 2017-01-31)").
 		Short('d').
 		String()
diff --git a/timetask/http.go b/timetask/http.go
index 6e73276..f236665 100644
--- a/timetask/http.go
+++ b/timetask/http.go
@@ -5,6 +5,7 @@ import (
 	"net/http/cookiejar"
 	"net/url"
 	"strconv"
+	"strings"
 
 	"golang.org/x/net/publicsuffix"
 )
@@ -97,9 +98,11 @@ func buildSubmissionParams(time_entry TimeEntry) url.Values {
 		time_entry.Date.Format("02/01/06"), // day/month/year
 	)
 
+	time_str := strconv.FormatFloat(time_entry.Time, 'f', 2, 64)
+	time_european_format := strings.Replace(time_str, ".", ",", 0)
 	v.Set(
 		"f_time0",
-		strconv.Itoa(time_entry.Time),
+		time_european_format,
 	)
 
 	var billable string
diff --git a/timetask/time_entry.go b/timetask/time_entry.go
index ff0ad1f..bb7a741 100644
--- a/timetask/time_entry.go
+++ b/timetask/time_entry.go
@@ -10,7 +10,7 @@ type TimeEntry struct {
 	Task        int
 	WorkType    int
 	Date        time.Time
-	Time        int
+	Time        float64
 	Billable    bool
 	Description string
 }
@@ -19,7 +19,7 @@ func NewTimeEntry(
 	profile Profile,
 	project Project,
 	date time.Time,
-	time int,
+	time float64,
 	description string,
 ) TimeEntry {
 	return TimeEntry{