feat: function name matches KService name

[zroubalik]

Signed-off-by: Zbynek Roubalik zroubali@redhat.com

• Error message printed before the actual creation:

$  ./func create test-                                                                                                                          
Error: Function name must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')

• Interactive session and incorrect name specified at the input -> error:

$ ./func create test- -c                                                                                                                             
Error: Function name must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')

• Interactive session with valid name, but with an invalid Project path later specified by user -> the prompt loops till valid name is entered:

$ ./func create test -c                                                                                                                               
Project path (/Users/zroubali/go/src/github.com/boson-project/func/test): test-
Error: Function name must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')
Project path (/Users/zroubali/go/src/github.com/boson-project/func/test): test
Runtime (node): 
Trigger (http): 

Fixes: #276

[lance]

Nice. I like that there are no longer two names (service and function).