Merge pull request #94 from oscarbenjamin/pr_bump_flint_v3rc1

Bump flint from v3a1 to v3rc1

Author: oscarbenjamin

bin/build_variables.sh

@@ -21,4 +21,4 @@ MPIRVER=3.0.0 # MPIR build no longer works (not clear where to download from)
 # These are the actual dependencies used (at least by default):
 GMPVER=6.3.0
 MPFRVER=4.1.0
-FLINTVER=3.0.0-alpha1
+FLINTVER=3.0.0-rc1