misc Lua Version difference fixes

spec/constraint_spec.lua

@@ -4,6 +4,7 @@ end)
 
 describe("Constraint", function()
    local kiwi = require("kiwi")
+   local LUA_VERSION = tonumber(_VERSION:match("%d+%.%d+"))
 
    describe("construction", function()
       local v, lhs
@@ -32,18 +33,31 @@ describe("Constraint", function()
          assert.equal(kiwi.strength.STRONG, c:strength())
       end)
 
+      -- TODO: standardize formatting
       it("formats well", function()
          local c = kiwi.Constraint(lhs)
-         assert.equal("1 foo + 1 == 0 | required", tostring(c))
+         if LUA_VERSION <= 5.2 then
+            assert.equal("1 foo + 1 == 0 | required", tostring(c))
+         else
+            assert.equal("1.0 foo + 1.0 == 0 | required", tostring(c))
+         end
 
          c = kiwi.Constraint(lhs * 2, nil, "GE", kiwi.strength.STRONG)
-         assert.equal("2 foo + 2 >= 0 | strong", tostring(c))
+         if LUA_VERSION <= 5.2 then
+            assert.equal("2 foo + 2 >= 0 | strong", tostring(c))
+         else
+            assert.equal("2.0 foo + 2.0 >= 0 | strong", tostring(c))
+         end
 
          c = kiwi.Constraint(lhs / 2, nil, "LE", kiwi.strength.MEDIUM)
          assert.equal("0.5 foo + 0.5 <= 0 | medium", tostring(c))
 
          c = kiwi.Constraint(lhs, kiwi.Expression(3), "GE", kiwi.strength.WEAK)
-         assert.equal("1 foo + -2 >= 0 | weak", tostring(c))
+         if LUA_VERSION <= 5.2 then
+            assert.equal("1 foo + -2 >= 0 | weak", tostring(c))
+         else
+            assert.equal("1.0 foo + -2.0 >= 0 | weak", tostring(c))
+         end
       end)
 
       it("rejects invalid args", function()