move sentry code around and add a stub unittest for it

ixsentry/CMakeLists.txt

@@ -0,0 +1,24 @@
+#
+# Author: Benjamin Sergeant
+# Copyright (c) 2019 Machine Zone, Inc. All rights reserved.
+#
+
+set (IXSENTRY_SOURCES
+    ixsentry/IXSentryClient.cpp
+)
+
+set (IXSENTRY_HEADERS
+    ixsentry/IXSentryClient.h
+)
+
+add_library(ixsentry STATIC
+  ${IXSENTRY_SOURCES}
+  ${IXSENTRY_HEADERS}
+)
+
+set(IXSENTRY_INCLUDE_DIRS
+    .
+    ../third_party
+    ../third_party/spdlog/include)
+
+target_include_directories( ixsentry PUBLIC ${IXSENTRY_INCLUDE_DIRS} )