Support strict function types

[macalinao]

Using tsconfig strict gives an error with the Provider type. I had to implement the following to silence the error:

diff --git a/node_modules/@compound-finance/compound-js/dist/nodejs/types/index.d.ts b/node_modules/@compound-finance/compound-js/dist/nodejs/types/index.d.ts
index 9fa7d65..6fa7580 100644
--- a/node_modules/@compound-finance/compound-js/dist/nodejs/types/index.d.ts
+++ b/node_modules/@compound-finance/compound-js/dist/nodejs/types/index.d.ts
@@ -71,15 +71,13 @@ export interface ProviderNetwork {
     id?: number;
     name?: string;
 }
-declare type GenericGetBalance = (addressOrName: string | number | Promise<string | number>, blockTag?: string | number | Promise<string | number>) => Promise<BigNumber>;
-declare type GenericGetTransactionCount = (addressOrName: string | number | Promise<string>, blockTag?: BlockTag | Promise<BlockTag>) => Promise<number>;
 declare type GenericSendTransaction = (transaction: string | Promise<string> | Deferrable<TransactionRequest>) => Promise<TransactionResponse>;
 export interface Provider extends AbstractSigner, FallbackProvider {
     connection?: Connection;
     _network: Network;
     call: AbstractSigner['call'] | FallbackProvider['call'];
-    getBalance: GenericGetBalance;
-    getTransactionCount: GenericGetTransactionCount;
+    getBalance: any;
+    getTransactionCount: any;
     resolveName: AbstractSigner['resolveName'] | FallbackProvider['resolveName'];
     sendTransaction: GenericSendTransaction;
     send?: (method: string, parameters: string[]) => any;

The solution is to treat Providers and Signers differently in the code, probably from some sort of disjoint union type. Unfortunately this may require some refactoring.