Doesn't compile if dependencies get updated

[davidperrenoud]

If you remove Example/Podfile.lock and do pod install again you get:

PODS:
  - BigInt (3.1.0):
    - SipHash (~> 1.2)
  - CoreEthereum (1.0.4):
    - ISO8601DateFormatter
  - CryptoSwift (0.13.0)
  - ISO8601DateFormatter (0.8)
  - Nimble (7.3.1)
  - PromisesObjC (1.2.3)
  - PromisesSwift (1.2.3):
    - PromisesObjC (= 1.2.3)
  - Quick (1.3.2)
  - SipHash (1.2.2)
  - uPortSDK (0.1.0):
    - BigInt
    - CryptoSwift
    - PromisesSwift
    - UPTEthereumSigner
  - UPTEthereumSigner (1.0.6):
    - CoreEthereum
    - Valet (~> 2.4.2)
  - Valet (2.4.2)

DEPENDENCIES:
  - BigInt
  - CryptoSwift
  - Nimble
  - PromisesSwift (~> 1.2.3)
  - Quick
  - uPortSDK (from `../`)

SPEC REPOS:
  https://github.com/cocoapods/specs.git:
    - BigInt
    - CoreEthereum
    - CryptoSwift
    - ISO8601DateFormatter
    - Nimble
    - PromisesObjC
    - PromisesSwift
    - Quick
    - SipHash
    - UPTEthereumSigner
    - Valet

EXTERNAL SOURCES:
  uPortSDK:
    :path: "../"

SPEC CHECKSUMS:
  BigInt: 76b5dfdfa3e2e478d4ffdf161aeede5502e2742f
  CoreEthereum: 25a58cd277d76ac3272d7e0bc6beea872175d587
  CryptoSwift: 16e78bebf567bad1c87b2d58f6547f25b74c31aa
  ISO8601DateFormatter: 4551b6ce4f83185425f583b0b3feb3c7b59b942c
  Nimble: 04f732da099ea4d153122aec8c2a88fd0c7219ae
  PromisesObjC: a3a4263d8a9260214267e0b3788d0f83466ad449
  PromisesSwift: f7f45c21986419e85f7c5b645ed8c6a2c10c04b4
  Quick: 2623cb30d7a7f41ca62f684f679586558f483d46
  SipHash: fad90a4683e420c52ef28063063dbbce248ea6d4
  uPortSDK: 4d1762d8b3de5c2146ad122cafc1d1b0f15482ca
  UPTEthereumSigner: 5ee010654e185a83fd640c5f493553623f4f1cce
  Valet: 14463ef24fab8fd5809044ecedb61484b799fdd6

PODFILE CHECKSUM: ceaefe797343147ea2abd308c572ad1e903be6a0

COCOAPODS: 1.5.3

When trying to build again in Xcode I get:

uport-ios-sdk-master/Example/Pods/UPTEthereumSigner/UPTEthereumSigner/Classes/EthereumSigner.h:3:9: 
'CoreBitcoin/BTCKey.h' file not found

Any idea?