Set the environment of the tests

Setting the PATH environment variable to the library output folder
solves false test positives on Windows as the test executable cannot
find the DLL.

test/CMakeLists.txt

@@ -77,7 +77,12 @@ macro(civetweb_add_test suite test_case)
   set(test "test-${suite}-${test_case}")
   string(TOLOWER "${test}" test)
   string(REGEX REPLACE "[^-A-Za-z0-9]" "-" test "${test}")
-  add_test(${test} civetweb-c-unit-test "--suite=${suite}" "--test-case=${test_case}")
+  add_test(
+    NAME ${test}
+    COMMAND civetweb-c-unit-test "--suite=${suite}" "--test-case=${test_case}")
+  string(REPLACE ";" "\\;" test_path "$ENV{PATH}")
+  set_tests_properties(${test} PROPERTIES
+    ENVIRONMENT "PATH=${test_path}\\;$<TARGET_FILE_DIR:c-library>")
 endmacro(civetweb_add_test)
 
 # Public API tests