Intruduce an E2E testing framework

Add a tests directory containing an E2E testing framework.
The tests are E2E in the sense that they use the public API of libkrun to
start a VM and run a test program in the guest.
Note that currently this is limited that there are no userspace program or
libraries (not even libc) in the guest apart from `guest-agent`, which is
part of the testing framework.

`guest-agent` is a statically linked Rust executable, that executes the guest
part of each test.

In the future this can be extended to run tests with specific images and allow
the use of system libraries by the test program.

Signed-off-by: Matej Hrica <[email protected]>

Author: mtjhrc

Cargo.lock

@@ -1,5 +1,5 @@
 [workspace]
-members = [ "krun-sys","src/libkrun"]
+members = ["krun-sys", "src/libkrun"]
 resolver = "2"
 
 [profile.dev]
@@ -8,3 +8,4 @@ resolver = "2"
 [profile.release]
 #panic = "abort"
 lto = true
+debug = true

Cargo.toml

@@ -0,0 +1,3 @@
+[workspace]
+members = ["runner", "guest-agent", "macros", "test_cases"]
+resolver = "2"

tests/Cargo.lock

@@ -0,0 +1,3 @@
+# End-to-end tests
+The testing framework here allows you to write code to configure libkrun (using the public API) and run some specific 
+code in the guest.  

tests/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "guest-agent"
+edition = "2021"
+
+[dependencies]
+test_cases = { path = "../test_cases", features = ["guest"] }
+anyhow = "1.0.95"