Separate test build from run

.travis.yml

@@ -5,4 +5,4 @@ before_install:
   - docker pull yglukhov/nim-base
 script:
   - docker run yglukhov/nim-base nim --version
-  - docker run -v "$(pwd):/project" -w /project yglukhov/nim-base nimble install -y && ./tests/test.sh
+  - docker run -v "$(pwd):/project" -w /project yglukhov/nim-base nimble install -y && ./tests/build_travis.sh && ./tests/test.sh

tests/build_test.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+nim c tests/code_stream_test.nim
+nim c tests/gas_meter_test.nim
+nim c tests/memory_test.nim
+nim c tests/stack_test.nim

tests/build_travis.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+export PATH=$PATH:/nim/bin/nim
+"$(dirname -- "$0")/build_test.sh"
+

tests/test.sh

@@ -1,9 +1,5 @@
 #!/bin/bash
 
-nim c tests/code_stream_test.nim
-nim c tests/gas_meter_test.nim
-nim c tests/memory_test.nim
-nim c tests/stack_test.nim
 ./tests/code_stream_test
 ./tests/gas_meter_test
 ./tests/memory_test