Update init CLI helptext

Author: darkowlzz

cmd/dep/init.go

@@ -25,14 +25,19 @@ Initialize the project at filepath root by parsing its dependencies, writing
 manifest and lock files, and vendoring the dependencies. If root isn't
 specified, use the current directory.
 
-The version of each dependency will reflect the current state of the GOPATH. If
-a dependency doesn't exist in the GOPATH, a version will be selected from the
-versions available from the upstream source per the following algorithm:
+By default, the dependencies are resolved over the network. A version will be
+selected from the versions available from the upstream source per the following
+algorithm:
 
  - Tags conforming to semver (sorted by semver rules)
  - Default branch(es) (sorted lexicographically)
  - Non-semver tags (sorted lexicographically)
 
+An alternate mode can be activated by passing -gopath. In this mode, version of
+each dependency will reflect the current state of the GOPATH. If a dependency
+doesn't exist in the GOPATH, a version will be selected based on the above
+network version selection algorithm.
+
 A Gopkg.toml file will be written with inferred version constraints for all
 direct dependencies. Gopkg.lock will be written with precise versions, and
 vendor/ will be populated with the precise versions written to Gopkg.lock.