Limit Upgradability

Prompted by #9, I should limit upgradability of this wrapper.
Any upstream change should get checked for its influence on obj_t
before getting imported.

@e35cf91's additional fields should still be compatible with <=0.8.0
binaries since the leading entries of obj_t hasn't changed and here
obj_t is allocated on Julia side

Author: xrq-phys

Project.toml

@@ -14,4 +14,4 @@ blis_jll = "6136c539-28a5-5bf0-87cc-b183200dce32"
 
 [compat]
 julia = "1.4"
-blis_jll = "0.8.0"
+blis_jll = "< 0.8.2"