message: Clean installation docs boost references
  Do not refer to boost versions older than 1.60.0.
  Boost is not necessary when compiling with a C++17 compiler.
diff: @@ -180,7 +180,6 @@ an additional option, `/Zc:__cplusplus` to opt into the correct definition of `_
  -G "Visual Studio 15 2017 Win64" \
  -DCMAKE_CXX_STANDARD=17 \
  -DCMAKE_CXX_FLAGS="/Zc:__cplusplus" \
  - -DBOOST_ROOT=C:\local\boost_1_59_0 \
  -DCMAKE_PREFIX_PATH=C:\mongo-c-driver \
  -DCMAKE_INSTALL_PREFIX=C:\mongo-cxx-driver \
  ```
  @@ -414,7 +413,7 @@ settings for a Debug x64 build as an example:
  ```xml
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
  <LinkIncremental>true</LinkIncremental>
  - <IncludePath>c:\local\boost_1_59_0\;C:\mongo-cxx-driver\include\mongocxx\v_noabi;C:\mongo-cxx-driver\include\bsoncxx\v_noabi;C:\mongo-c-driver\include\libmongoc-1.0;C:\mongo-c-driver\include\libbson-1.0;$(IncludePath)</IncludePath>
  + <IncludePath>c:\local\boost_1_60_0\;C:\mongo-cxx-driver\include\mongocxx\v_noabi;C:\mongo-cxx-driver\include\bsoncxx\v_noabi;C:\mongo-c-driver\include\libmongoc-1.0;C:\mongo-c-driver\include\libbson-1.0;$(IncludePath)</IncludePath>
  <LibraryPath>c:\mongo-c-driver\lib\;c:\mongo-cxx-driver\lib\;$(LibraryPath)</LibraryPath>
  </PropertyGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
  