Run runnableExamples in CI (#105)

Author: konsumlamm

bigints.nimble

@@ -18,6 +18,7 @@ task test, "Test bigints":
       echo "  using " & gc & " GC"
       for file in ["tbigints.nim", "tbugs.nim"]:
         exec "nim r --hints:off --experimental:strictFuncs --backend:" & backend & " --gc:" & gc & " tests/" & file
+      exec "nim doc --hints:off --backend:" & backend & " --gc:" & gc & " src/bigints.nim"
 
 task checkExamples, "Check examples":
   echo "checking examples"

src/bigints.nim

@@ -1145,7 +1145,7 @@ func invmod*(a, modulus: BigInt): BigInt =
   ## Compute the modular inverse of `a` modulo `modulus`.
   ## The return value is always in the range `[1, modulus-1]`
   runnableExamples:
-    invmod(3.initBigInt, 7.initBigInt) = 5.initBigInt
+    assert invmod(3.initBigInt, 7.initBigInt) == 5.initBigInt
 
   # extended Euclidean algorithm
   if modulus.isZero: