Update README.md

Remove external dependency (keeping mage) as well as updating why Mage is required.

README.md

@@ -31,16 +31,9 @@ go get -u github.com/rudi9719/kbtui
 ```
 Or you can do the following:
 ```
-go get ./...
-go run build.go
+go get github.com/magefile/mage/mage
 go run build.go {build, buildBeta... etc}
 ./kbtui
 ```
-
-You may see an error with `go get ./...` about PATHs, that may be safely ignored.
-
-If you see an error about a missing dependancy during a build, you'll want to resolve that.
-
-
-Occasionally when [@dxb](https://keybase.io/dxb) updates his API it will be necessary to run
-`go get -u ./...` or `go get -u samhofi.us/x/keybase`
+Mage is a requirement for building `kbtui` as it will automatically handle/manage imports as well as mage is used to generate the 
+file for emoji completion.