Canasta should verify dependencies before doing anything

[hexmode]

The cli should verify that docker-compose, etc are available when it is invoked with any command that will use them.

For instance: canasta help does not require any external tools and it should (continue to) just work.

However canasta create does require the installation of docker-compose and it should refuse to run if it cannot find it. Otherwise, you end up with this sort of frustrating dialog:

$ sudo ./canasta create
Enter Wiki Name: Test
Enter Canasta ID: test
Enter admin name: WikiSysop
Enter the admin password (Press Enter to autogenerate the password): 
Setting up Canasta
exec: "docker-compose": executable file not found in $PATH
$

[jeffw16]

@amalpaul54111 Please take a look at this