Make "morph checkout" require a repository parameter

Instead of hard-coding "baserock:morphs" as the repository we check out
from, we want to allow people to check out from arbitrary repositories
with system and stratum morphologies.

This commit adds a mandatory repository parameter to "morph checkout".

This parameter can either be an aliased repo, e.g. baserock:morphs, or
a full repo URL such as ssh://gitano@git.baserock.org/baserock/morphs.
When cloning the actual repository into a local directory, the following
happens:

For alias repos baserock:morphs and baserock:foo/bar, the repositories
would be cloned into the directories

  $workspace/$branch/baserock:morphs

and

  $workspace/$branch/baserock:foo/bar.

For repos specified using full URLs, the scheme and .git suffix (if
present) are stripped off. The above ssh example would be cloned into
the following directory:

  $workspace/$branch/gitano@git.baserock.org/baserock/morphs

This commit also adjusts all affected tests and adds a new test to
verify that checking out from full repo URLs works as expected.

1 files changed, 3 insertions, 0 deletions

diff --git a/tests.branching/setup b/tests.branching/setup
index 1705c9b4..51092cea 100755
--- a/tests.branching/setup
+++ b/tests.branching/setup
@@ -56,6 +56,9 @@ mkdir "$DATADIR/workspace"
 # Create a fake morphs repository
 mkdir "$DATADIR/morphs"
 
+## Create a link to this repo that has a .git suffix
+ln -s "$DATADIR/morphs" "$DATADIR/morphs.git"
+
 cat <<EOF > "$DATADIR/morphs/hello-system.morph"
 {
     "name": "hello-system",