Release 1.0.0-beta2

This is a beta for the upcoming 1.0.0 release.

Major changes since the last beta:

• Added support for LLVM 7, 8 and 9
• Made CMake build non-experimental, now recommended
• Deprecated Make and NMake builds
• Fixes to better support macOS Mojave and Catalina (for caveats see #435)
• Substantial improvements to detection of VS installation on Windows
• Code base is now formatted with clang-format

For accumulated changes since the last major release, see https://github.com/terralang/terra/blob/master/CHANGES.md

A note on the binaries:

• The Linux binaries were created on Ubuntu 16.04, and may not work on other distros. We're working on improving portability but this is an ongoing process.
• All binaries were compiled against CUDA 9.2 and LLVM 6.