tests: add a testcase for applying patches

This adds a test where we clone a git and a hg repo and apply a single
patch and later a quilt series on each of them.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

tests/test_patch/patches/hello/001.patch

@@ -0,0 +1,8 @@
+diff --git a/Makefile b/Makefile
+--- a/Makefile
++++ b/Makefile
+@@ -1,1 +1,4 @@
+ all: hello
++
++clean:
++	rm -f hello

tests/test_patch/patches/hello/quilt/001.patch

@@ -0,0 +1,8 @@
+diff --git a/Makefile b/Makefile
+--- a/Makefile
++++ b/Makefile
+@@ -1,4 +1,1 @@
+ all: hello
+-
+-clean:
+-	rm -f hello

tests/test_patch/patches/hello/quilt/002.patch

@@ -0,0 +1,8 @@
+diff --git a/Makefile b/Makefile
+--- a/Makefile
++++ b/Makefile
+@@ -1,1 +1,4 @@
+ all: hello
++
++clean:
++	rm -f hello

tests/test_patch/patches/hello/quilt/series

@@ -0,0 +1,4 @@
+# test comment
+# this is a revert of the other 001 we applied without quilt
+001.patch # first patch
+002.patch