unit-test: Use a newer googletest

The last googletest release was 2 years ago and is notably missing built
in pkgconfig support. Since the release upstream has added pkgconfig
support that is divergent from the pkgconfig files we patched onto their
old release. Instead of backporting those pkgconfig files, just update
to use a snapshot of googletest until a new release is made.

Tested:
    Test cases still work for sdbusplus and phosphor-logging.

Change-Id: I0d6f4b7bf747860ba2cbd072bfed275053456ae0
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 26ff544..16437e4 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -92,15 +92,11 @@
 RUN pip install inflection
 RUN pip install pycodestyle
 
-# Googletest doesn't support pkg-config properly and therefore yocto uses a
-# patch to fix it.  This grabs and applies that patch and then builds it.
-RUN wget https://github.com/google/googletest/archive/release-1.8.0.tar.gz
-RUN tar -xzf release-1.8.0.tar.gz
-RUN wget -O googletest-release-1.8.0/Add-pkg-config-support.patch \
-http://cgit.openembedded.org/meta-openembedded/plain/meta-oe/recipes-test/gtest/gtest/Add-pkg-config-support.patch?h=rocko
-RUN cd googletest-release-1.8.0 && patch -p1 -i Add-pkg-config-support.patch
-RUN cd googletest-release-1.8.0 && \
-cmake -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_INSTALL_LIBDIR:PATH=/usr/lib -DCMAKE_INSTALL_INCLUDEDIR:PATH=/usr/include . && \
+# Snapshot from 2018-06-14
+RUN wget -O googletest.tar.gz https://github.com/google/googletest/archive/ba96d0b1161f540656efdaed035b3c062b60e006.tar.gz
+RUN tar -xzf googletest.tar.gz
+RUN cd googletest-* && \
+cmake -DBUILD_GTEST=ON -DBUILD_GMOCK=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX:PATH=/usr . && \
 make && make install
 
 RUN wget https://github.com/USCiLab/cereal/archive/v1.2.2.tar.gz