add go-flags

Author: linyows

go.mod

@@ -1,3 +1,6 @@
 module github.com/linyows/git-semv
 
-require github.com/blang/semver v3.5.1+incompatible
+require (
+	github.com/blang/semver v3.5.1+incompatible
+	github.com/jessevdk/go-flags v1.4.0
+)

go.sum

@@ -1,2 +1,4 @@
 github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
 github.com/blang/semver v3.5.1+incompatible/go.mod h1:kRBLl5iJ+tD4TcOOxsy/0fnwebNt5EWlYSAyrTnjyyk=
+github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
+github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=